HK1142746A

HK1142746A - Multiple network access system and method

Info

Publication number: HK1142746A
Application number: HK10109161.2A
Authority: HK
Inventors: D‧P‧康纳斯; G‧W‧玛什
Original assignee: 蔚蓝公司
Priority date: 2007-01-26
Filing date: 2008-01-10
Publication date: 2010-12-10

Description

Multiple network access system and method

Technical Field

The present invention relates generally to wireless network systems and to a system and method for accessing two or more networks in which a wireless communication device, such as a handset, personal computer, Personal Digital Assistant (PDA), or the like, may alternate or switch between at least two networks on orthogonal channels, one of which may be dedicated to the transmission of multimedia data.

Background

Wireless users are continually demanding new services from wireless service providers. One new service that is expected by particularly high user demand is wireless video service. Some industry experts describe wireless video as an interlace of the two largest unprecedented achievements for consumer electronics, cellular phones and televisions.

Providing video services over wireless communication networks presents a number of challenges. The amount of data that needs to be transmitted to provide video services to users is very large compared to the effective capacity of conventional bi-directional networks. Some video service networks may be implemented separately from conventional bi-directional service networks. The separate network implementation allows the video service network to be specifically designed for efficient video content dissemination.

High-functionality subscriber stations will provide a wide variety of services to subscribers. To do this, the subscriber station apparatus may need to access a plurality of different wireless communication networks.

Accordingly, there is a need for improved systems, apparatuses, and techniques for accessing multiple wireless networks from a single device.

Disclosure of Invention

Embodiments described herein provide methods, systems, media and devices for accessing at least two different networks through a wireless communication device.

According to one aspect of the invention, in one embodiment, a method for operating a wireless communication device that communicates with at least two different wireless networks using a single radio frequency modem includes connecting the wireless device to a first wireless network through a Radio Frequency (RF) modem. The wireless device is then disconnected from the first wireless network at a predetermined time that is before the start time of the selected event in the second wireless network. Connecting the wireless device to a second wireless network using the same RF modem prior to a start time of a selected event, collecting at least a portion of event data associated with the selected event at the wireless device, the selected event transmitted from the second wireless network after the start time of the selected event. The wireless device is then disconnected from the second wireless network after at least a portion of the event data is collected, and the wireless device is reconnected to the first wireless network after being disconnected from the second wireless network.

In another embodiment, a subscriber station, such as a wireless communication device, operates on at least two different wireless networks. The subscriber station includes a Radio Frequency (RF) modem configured to connect to a first wireless network and a second wireless network. The subscriber station also includes a network connection arbiter module configured to store timing information for event data bursts associated with selected events of the second wireless network, and to control the RF modem to connect to the first wireless network when data bursts associated with selected events do not occur, and to control the RF modem to connect to the second wireless network when data bursts associated with selected events occur. The subscriber station includes an application module that collects at least a portion of the event data by collecting event data from event data bursts associated with selected events while the RF modem is connected to the second wireless network.

In another embodiment of the present invention, a method of operating a communication device to communicate with at least two different networks using a single modem includes establishing a first connection with a first wireless network through the modem. Second network status information associated with the second wireless network is then received over the first connection with the first wireless network, and a second connection is established with the second wireless network through the modem using the second network status information.

Another embodiment is directed to a wireless communication device for communicating over at least two wireless networks, the wireless communication device comprising a Radio Frequency (RF) modem, and a network connection arbiter module connected to the RF modem. The network connection arbiter module controls the RF modem to establish a first connection with the first wireless network and to establish a second connection with the second wireless network on an alternating basis. The device also includes an application module connected to the RF modem and the network connection arbiter module and receiving second network status information associated with the second wireless network over the first connection established with the first wireless network and sending the second network status information to the RF modem for establishing a second connection with the second wireless network.

In a further embodiment, a multi-network system includes a first wireless network having a plurality of base stations. The system also includes a second wireless network having a plurality of base stations. There is also at least one wireless communication device, or subscriber station, in the system that includes a Radio Frequency (RF) modem configured to connect to the first wireless network and the second wireless network. The wireless communication device also includes a network connection arbiter module configured to store timing information for bursts of event data associated with selected events of the second wireless network. The network connection arbiter also controls the RF modem to connect to the first wireless network when a data burst associated with the selected event does not occur and controls the RF modem to connect to the second wireless network when a data burst associated with the selected event occurs. In addition, the wireless communication device includes an application module that collects at least a portion of the event data by collecting event data from event data bursts associated with the selected event while the RF modem is connected to the second wireless network.

Other features and advantages of the present invention will become more readily apparent to those of ordinary skill in the art after reviewing the following detailed description and accompanying drawings.

Drawings

The details of the present invention, both as to its structure and operation, will be best understood from the following detailed description of certain exemplary embodiments of the invention, when read in conjunction with the accompanying drawings, in which like reference numerals refer to like parts in the embodiments, and in which:

fig. 1 is a block diagram of a multiple network access system according to one embodiment of the invention;

FIG. 2 is a block diagram illustrating the network connection arbiter module of FIG. 1 in greater detail;

FIG. 3A is a block diagram illustrating the use of network state parameters to associate and connect with a network in accordance with an illustrative embodiment;

FIG. 3B is a block diagram illustrating the use of network state parameters to associate and connect with multiple networks in accordance with an illustrative embodiment;

FIG. 4 is a block diagram illustrating an exemplary system embodiment of FIG. 1 in which two networks are utilized by a subscriber station;

FIG. 5 is a flow diagram of an exemplary embodiment of a network handover method for handover between a bidirectional network and a unidirectional network;

FIG. 6 is a network switch timeline in accordance with an exemplary embodiment of the present invention;

FIG. 7 is an enlarged view illustrating time-sliced broadcast data based on the events shown in FIG. 6; and

fig. 8 is a flow diagram of an alternative exemplary embodiment of a network switching method for switching between a bidirectional network and a unidirectional network using time sliced data.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

Fig. 1 through 8 illustrate methods and systems for accessing two or more wireless networks from a single device according to exemplary embodiments of the present invention. In particular, exemplary embodiments of the present invention are directed to wireless communication devices, such as Subscriber Stations (SSs), that switch between two different networks using a single Radio Frequency (RF) modem (transceiver). A Subscriber Station (SS) may be a completely mobile, portable, or fixed device such as a cellular phone, a Personal Media Player (PMP), a Personal Digital Assistant (PDA), a Personal Video Recorder (PVR), a personal computer, a wall-mounted wireless television, and the like.

After reading this description it will become apparent to one skilled in the art how to implement the invention in various alternative embodiments and alternative applications. However, while various embodiments of the present invention will be described herein, it should be understood that they have been presented by way of example only, and not limitation. As such, this detailed description of various alternative embodiments should not be construed to limit the scope or breadth of the present invention as set forth in the appended claims.

Fig. 1 illustrates a multiple network access system in accordance with one embodiment in which a subscriber station is capable of accessing two different networks. A wireless network typically includes a plurality of base stations dispersed throughout different geographic regions. The Base Station (BS) may be a conventional wide area base station or Access Point (AP), a gateway, a portal, or other wireless entry port to the network. A wireless network may also include fixed or mobile wireless subscriber stations or communication devices. For example, a fixed wireless subscriber station may be located in a home or office building.

As illustrated in fig. 1, a subscriber station 10 is capable of accessing first and second networks 12 and 14 over wireless communication channels, such as orthogonal or non-interfering channels 16, 18, via a single modem 20. Subscriber station 10 is connected to networks 12, 14 via wireless channels 16, 18, respectively. The modem 20 comprises a station (both transmitter TX and receiver RX) communicating with at least one antenna and a baseband receiver with a main interface.

In one embodiment, the subscriber station connects to the network when an RF module in the subscriber station tunes to the frequency band used by the network, and the subscriber station synchronizes to the waveform arriving from the network so that the PHY module and MAC module in the subscriber station can receive information over the network. Connecting to a given network does not necessarily mean any form of logical connection or association with the network. Likewise, disconnection from a given network does not necessarily mean that a logical connection, registration, or association with the network has been previously established, torn down. The concepts of "associating" with and "connecting" to a network will be discussed in further detail herein.

In one embodiment, each network 12 and 14 may have a separate set of base stations. Alternatively, the same physical base station or location may be used on both networks 12 and 14. For example, a base station may have a separate transmitter or access node for each network 12 and 14. Both networks 12 and 14 may be unidirectional networks. Alternatively, networks 12 and 14 may both be two-way communication networks, or one network may be a single wire but the other is two-way. The exemplary embodiments described below with respect to fig. 4 through 8 include a bi-directional network and another unidirectional network.

In a bidirectional network, a subscriber station may receive information and transmit information over an air interface channel of the bidirectional network. In a unidirectional network, a subscriber station can only receive information from an air interface channel of the unidirectional network. Further, in some embodiments, the subscriber station may utilize a reverse channel communication link to access a back-end system feeding back the unidirectional network in addition to the air interface channel of the unidirectional network. The back channel communication link may be a low-rate non-real-time back channel, such as through a PC docking station of the subscriber station, a separate wireless back channel, such as WIFI, or some other back channel type that allows the subscriber station to transmit at least a limited amount of information to the back-end system. For example, in one embodiment of a unidirectional network, the subscriber station may subscribe to or pay for programming using the reverse channel communication link to gain access, etc. The reverse channel communication link is capable of communicating with a back-end system module associated with the unidirectional wireless network via the internet. In this case, the subscriber station may use the reverse channel communication link to pay for and/or subscribe to content programming in which the access code is downloaded to the subscriber station over the reverse channel communication link. The next time the subscriber station connects to the unidirectional wireless network, the subscriber station is able to receive, extract and decode (using the access code) the ordered program from the transmitted signal of the unidirectional network.

The network modem 20 may have only a Radio Frequency (RF) receiver if both networks are unidirectional, or the modem 20 may have an RF transmitter/receiver (modem) if at least one of the networks is a bidirectional network with both uplink and downlink. In one embodiment, the second network 14 is a digital video broadcast-handheld (DVB-H) over a WIMAX unidirectional broadcast network, such as one of the embodiments of a wireless broadcast network described in U.S. patent application Ser. No. 11/623032 entitled "Wireless broadcast System", filed on 12.1.2007, the contents of which are incorporated herein by reference.

Although only one subscriber station 10 is illustrated in fig. 1, a plurality of subscriber stations 10 capable of communicating with two different networks via a single modem platform may be included in the system. Further, in further embodiments, the system may be extended to allow communication with more than two networks through the same modem.

Returning to fig. 1, the wireless modem 20 communicates with an application processor 30 and a network connection arbiter (NAA) module 32. The network connection arbiter module 32 controls switching between multiple networks, such as between two networks 12 and 14 in one embodiment. In one embodiment, the application module 30 has a first network application processing module 34 that controls the processing of first network data, and a second network application processing module 35 that controls the processing of second network data.

In one embodiment, the data processing can include processing incoming data received from the various networks to convert the incoming data into a format suitable for presentation to the user of the user station 10. In one embodiment, if the subscriber station 10 is in communication with a bidirectional network in one of the networks, the associated application processing module may also include processing the user data into a format suitable for transmission from the subscriber station 10 over the bidirectional network via the modem 20.

In one embodiment, the first network 12 may be a two-way wireless communication network, while the second network 14 may be a one-way network. The first network 12 may be a two-way wireless communication network such as a conventional two-way WIMAX network as defined in the WIMAX forum. WIMAX networks are a non-profit organization that strives to facilitate the deployment of broadband wireless networks by ensuring the compatibility and interoperability of broadband wireless devices in accordance with the institute of electrical and electronics engineers' IEEE802.16 protocol and the ETSIHIPERMAN standard. As mentioned above, the second network may be a unidirectional network for handheld digital video broadcast (DVB-H) based distribution over a WIMAX based wireless distributed unidirectional network for distribution of multimedia content, such as video, to a plurality of subscriber stations.

One advantage of deploying a bi-directional network in the same geographical area as a unidirectional multimedia distribution network is that the subscriber stations can be built with an efficient architecture that is capable of communicating with both networks described herein.

Figure 2 is a block diagram illustrating one embodiment of the network connection arbiter module 32 in further detail. As shown in fig. 2, the network connection arbiter module 32 includes a network switch controller module 36 in communication with the modem 20 (see fig. 1), a data routing controller 44, and a data storage module 38. In one embodiment, data storage module 38 includes a first storage area 40 for storing network status information regarding first network 12 and a second storage area 42 for storing network status information regarding second network 14. The timer module 45 communicates with the network handover controller module 36 and the data storage module 38 to provide timing information for use in controlling handovers between the networks 12 and 14. The data routing controller 44 provides routing control of data between the modem 20 and one of the network application modules 34 and 35, depending on which of the networks 12 and 14 the network switch controller module 36 indicates to which of the networks 20 the modem 20 is connected. In this regard, the data routing controller 44 controls the aforementioned data routing in accordance with the network switch signal received from the network switch controller 36. The data routing controller 44 communicates with the network application modules 34 and 35 to provide them with control signals for directing the proper routing of data between the modem 20 and one or the other network application modules 34 and 35. It will be appreciated that the data storage module 38 may also include other data storage such as program instructions, operational data and parameters, etc. for the NAA module 32.

In one embodiment, the state information for the first and second networks 12 and 14 stored in the first and second memory regions 40 and 42 includes information that allows the modem 20 to tune to, synchronize with, and associate with (if appropriate) the respective networks so that the subscriber station 10 can receive and synchronize data streams from the networks over the associated air link channels. As previously mentioned, the concept of association refers to the co-maintaining of a mutual two-way logical connection and related state information in the subscriber station and the serving base station of the network with which the subscriber station is associated. In one example, when a subscriber station connects to a network and registers with a particular base station in the network, an association is formed that includes, but is not limited to, basic compatibility of the subscriber station and the base station, security associations, IP addresses, and operating parameters. For example, the state information may include at least one or more of the following information or communication parameters of the respective networks:

1. frequency of

2. Timing information (frame number of current frame)

3. Safety information (decryption key)

4. The base station/access point or transmitter identifies the BSID. The BSID may change as the subscriber station 10 moves to a new macrocell or area covered by a new base station and upgrades to the stored information as necessary as the change occurs.

5. Connection Identifier (CID) of network

6. Expected leading index

7. Time base offset (network time)

Stored network state information or other communication parameters may be upgraded as necessary. For example, the status information may be updated each time the subscriber station moves into the network, the subscriber station reconnects to the network, or moves into the coverage area of a different network. In addition, a frame counter may be included in the timer module 45, which allows the NAA to know the current frame number of the data stream transmitted from the network even when the modem 20 of the subscriber station 10 is connected to other networks. In this manner, the current frame number for each network may be stored in the data store 38 of the NAA module 32 as part of the network status information. The identity in the base station or access point, network status information can also be upgraded when a subscriber station passes through the coverage area of one base station into the coverage area of a different base station.

The network switch controller module 36 is also capable of determining when the subscriber station 10 should connect to the network. For example, the network switching module 36 can determine whether the subscriber station 10 should connect to the network based on previously programmed instructions, input signals, user inputs, etc., which can be stored in the data store 38, as described in more detail below. The network switch controller module 36 is also capable of providing the modem 20 with associated network status information when a switch from one network to another is commanded.

Fig. 3A illustrates a flow diagram for connecting to a network using network state information according to an example embodiment. When the RF module in the subscriber station is tuned to the frequency band used by the network, the subscriber station connects to the network and is synchronized with the arriving waveform so that the PHY and MAC modules in the subscriber station can receive information from the network and transmit information (if a bidirectional network) to the network. Thus, the concept of a connection may be understood as a physical connection of the subscriber station modem to the received waveform, and this does not mean that an "association" has been established between the subscriber station and the network, where "association" may be understood as a logical connection. In another embodiment, instead of a frequency division based network, the network may be a code division based network or a time division based network, in which case the modem adjusts the coding parameters or timing parameters to connect to the network.

A subscriber station may be "associated" with a bi-directional network or in communication with a unidirectional network and intermittently switched between the two networks by connecting to and disconnecting from each network in a coordinated manner. In the following description, a subscriber station is "associated" with the network with which it is attempting to communicate. The associated processing can be changed from one network to another. For example, in a typical conventional bi-directional network, a subscriber station is associated with the network when the subscriber station registers with the network and negotiates communication traffic with the network. The subscriber station typically remains associated with the bidirectional network until the subscriber station is powered off. The "association" between the subscriber station and the bidirectional network is a concept of a two-way logical connection and state information of the connection can be stored in both the base station and the subscriber station. When a subscriber station is associated with a bidirectional network, the subscriber station can intermittently connect to and disconnect from the network without losing association with the network. In particular, although the subscriber station has been disconnected from and connected to the bidirectional network, the subscriber station is not disassociated from the bidirectional network.

In one embodiment, the subscriber station does not need to associate with the unidirectional network prior to connecting with the unidirectional network since no uplink is supported in the unidirectional network for the interconnection.

Returning to FIG. 3A, the flow begins at block 301. The flow continues to block 303 where network information for the appropriate desired network is retrieved from the data store. The flow continues to block 305 where the subscriber station connects to the desired network using the acquired network information. For example, a subscriber station can connect to a desired network by tuning the subscriber station's modem to the frequency band used by the network, and then the subscriber station synchronizes with the waveform received from the network so that the PHY module and MAC module in the subscriber station can receive information over the network. The flow continues to block 307 where the network state information is updated, if necessary, while the subscriber station is connected to the network. In addition, the network state information in the data storage module may be upgraded at the time of connection, at the time of connection having been established, at the time of disconnection, or at the time of disconnection. The flow continues to block 309 and ends.

Fig. 3B is a flow diagram illustrating associating and connecting (if appropriate) with each multiple network using network state information in accordance with an example embodiment. The flow begins at block 311 and continues to block 313 where network status information for the first network is obtained from the data store. The flow continues to block 315 where the subscriber station establishes a connection with the first network by tuning to the first network and synchronizing with the network using the first network state information. In this case, the first network is bi-directional, and the subscriber station is also capable of establishing an association with the first network by, for example, registering and negotiating traffic with the first network. The flow continues to block 317 and the network state information for the first network is upgraded if necessary while connected to the network. In addition, the network state information in the data storage module may be upgraded at the time of connection, at the time of connection having been established, at the time of disconnection, or at the time of disconnection.

The flow continues to block 319 where network state information for the second network is obtained via the first network. For example, after the subscriber station connects to the first network, the subscriber station can receive, via the first network, or download, network state information associated with the second network. The flow continues to block 321 where the subscriber station disconnects from the first network and connects to the second network using the second network state information obtained via the first network. The flow continues to block 323 where the flow ends. In this case, the subscriber station is prepared for connection to the second network in advance by having previously acquired network state information of the second network while it is connected to the first network. Alternatively, the second network status information obtained in block 319 may be obtained from a memory or a replacement device.

Fig. 4 is a block diagram illustrating further details of an exemplary embodiment of the system of fig. 1, in which two networks are utilized by a subscriber station in fig. 1. Fig. 4 includes further details of the subscriber station 10 and the first and second networks 12 and 14. As shown in fig. 4, the subscriber station 10 includes a first network application module 34 and a second network application module 35, wherein the second network application processor 35 includes an application layer decoder module 51 and a data link layer module 52, such as a multiprotocol encapsulator forward error correction (MPE-FEC) receiver, which receives TS packets from the modem 20. The first application module 34 communicates with a network layer module 54, such as an IP network layer module that communicates with the modem 20 for sending and receiving data packets. The first application module 34 may include various types of applications, such as a meta-content information module 53 shown in fig. 4, that obtains meta-information about content distribution over a network, such as network 14.

As illustrated in fig. 4, the first and second network application processors 34 and 35 are in communication with the modem 20, the modem 20 being capable of communicating with the first and second networks 12 and 14, respectively. The modem 20 is capable of transmitting and receiving data from the first and second networks 12 and 14 via the wireless communication links 16 and 18. Subscriber station 10 further includes a network connection arbiter 32 for controlling the switching of modem 20 between networks 12 and 14, as discussed herein. In one embodiment, the first network 12 is a bidirectional network and the second network 14 is a unidirectional network.

In some embodiments, some of the modules or layers illustrated in figure 4 for the subscriber station 10, e.g., the modem 20, can be implemented in the subscriber station 10, while other modules or layers, such as the application layer decoder module 51 and the data link layer module 52, can be implemented in the devices to which the subscriber station is connected, as may occur.

In the embodiment depicted in fig. 4, the second network 14 is a unidirectional network and the first network 12 is a bidirectional network. The second network 14 is used to distribute multimedia content to multiple subscriber stations and includes an application encoder module 65 that provides Internet Protocol (IP) packets of content to an IP encapsulator module 66. An IP encapsulator module 66 is located at the top of the data link layer, encapsulates IP packets with outer channel coding and time interleaving information, and then informs a transmit module 67 located in the base station of the resulting MPEG-2 Transport Stream (TS) packets. The air interface protocol governs the operation of the transmit module 67 and the receive module in the modem 20. The transmit module 67 includes a MAC module, a PHY module, and an RF module, wherein the MAC module receives TS packets from the IP encapsulator module 66 and forwards the TS packets to the PHY module, which processes the packets for transmission, and sends the packets to the RF module for transmission over the network. Data transmitted from the transmit module 67 to the modem 20 over the air interface channel 18 may be included in one or more frames.

The modem 20, which also includes the MAC, PHY and RF modules, outputs data received from the network 14 as MPEG-2TS packets to the second network application module 35, so that the data link layer module 52 receives MPEG-2TS packets and outputs IP packets to the application decoder module 51, which decodes packets used by the subscriber station, such as packets in video playback. In the data link layer module 52, a receiver with forward error correction multiprotocol encapsulation (MPE-FEC) can extract the time interleaving information and provide input to the receiver in the modem 20 and to the network connection arbiter (NAA) module 32 based on this information. The content of the time-interleaved information, referred to as "time-slicing", is described further below in connection with fig. 6, 7 and 8.

In one embodiment, the unidirectional network 14 is capable of transmitting multiple content streams that have been aggregated into an aggregate interleaved content stream. Once the application decoder module 51 is synchronized with the IP stream received from the data link layer module 52, it can select one or more content stream extractions for storage or display to the user. The content stream can include, for example, movies, games, video broadcasts, broadcast television programs, or other multimedia data.

When the subscriber station 10 is connected to the bidirectional network 12, the first network application module 34 is able to communicate with the network layer module 54, for example, by sending and receiving IP data packets to and from the network layer module 54. The network layer data module 54 is also in communication with the MAC layer of the modem 20, which is capable of transferring data to and from the first application processor module 34.

The first network 12 can include an application module 61, a network layer module 62 and a transceiver module 63 in the base station. The transceiver module 63 includes a MAC, PHY, and RF module. In one embodiment, the application module 61 in the first network 12 includes various applications such as an internal meta-information server 64 for providing information to the content meta-information module 53 in the first application processor 34 in the user station 10. The application module 61 need not be co-located with other modules of the first network 12. For example, the application module 61 can run on a processor or server in another network, such as the Internet, that is in communication with the network layer module 62 of the first network 12, and the application module 61 can include applications such as VOIP, IM, email, and the like.

The content meta-information obtained from the content meta-information server 64 can provide information about a network, such as the unidirectional network 14. In this case, meta information about the unidirectional network 14 and content distributed thereon can be acquired from the bidirectional network 12.

In one embodiment, where the subscriber station 10 is connected to the bidirectional network 14, the content meta-information module 53 is capable of obtaining content meta-information about the network 12 from the content meta-information server 64. The content meta information module 53 communicates directly or indirectly with the application decoder module 51 and the data link layer MPF-FEC receiver module 52 and provides them with content meta information about the second network, such as an Electronic Service Guide (ESG), program detailed information (PSI), and other information about the content distributed over the unidirectional network 14.

In one embodiment, the content meta-information module 53 is capable of receiving content meta-information over the first network 12 regarding the timing or occurrence of an event, such as a broadcast video program on the second network. In another embodiment, first application module 34 may be capable of receiving network status information regarding second network 14 via first network 12.

In another embodiment, content meta-information about what content is included in a unidirectional network, such as the second network 14 transmission, can be received over the first network 12 or in a signal received from the second network 14. For example, an Electronic Service Guide (ESG) can be communicated to the subscriber station 10 through the first network 12 or the second network 14. In one embodiment, an Electronic Service Guide (ESG) is displayed on a screen of a predetermined broadcast program, allowing a viewer to guide the guide through time, title, channel, genre, discover and select content. In one embodiment, when providing an ESG to a subscriber station, such as a subscriber station connected to a Personal Multimedia Player (PMP), the guide enables a viewer to record a broadcast program received and extracted from a signal of a unidirectional network for later viewing. Typical elements of an ESG include a graphical user interface capable of displaying program files, descriptive information such as synopsis, actors, director, time of production, and other information.

ESG information data is typically transmitted at very low data rates in a unidirectional transmission of content transmission data packets, or in conjunction with the transmission of content data packets in a unidirectional network-specific data channel. The data rate of the ESG transmission in such a unidirectional network is kept at a low level so that the transmission of the ESG and other metadata required by the subscriber station to access the content from the unidirectional network does not consume an excessive amount of system capacity. However, the low transmission rate causes a delay in initializing the subscriber station and the subscriber station slowly accumulates ESG data through the unidirectional network. Thus, in some embodiments, it is preferred that the subscriber station obtain ESG information from the content meta-information server 64 over the bidirectional network 12 in response to a query from the content meta-information module 53.

In addition to the ESG, other content meta information may be transmitted at a low data rate in a unidirectional network. For example, program description information (PSI) may be transmitted in a unidirectional network. PSI is metadata defined by the MPEG-2 standard. PSI data may contain a number of tables, including the following: PAT (program association table), CAT (conditional access table), PMT (program map table), and NIT (network information table). This information can be used by the subscriber station to map a particular program to its associated component data stream (video, audio, etc.) and also to map an IP address to each component data stream.

As is known, the content metadata information about the unidirectional network signal may be contained in the unidirectional signal itself, or it may be received from a different network, such as the bidirectional network 14. For example, as previously described with respect to fig. 3, information regarding the signals of unidirectional network 14 may be received by subscriber station 10 from unidirectional network 14 itself, or from bidirectional network 12.

The data streams transmitted between the first network 12 and the subscriber station 10 over the air link channel 16 may be provided in a variety of formats, such as audio, stored data files, metadata, moving picture experts group-2 (MPEG-2), windows media video, and other formats, and the first network application module 34 may be adapted to receive and process a variety of different types of content in a manner well known in the art. When connected to any network, the subscriber station 10 may perform a number of functions, for example, when it is time to connect to the other network, it searches for other networks, it receives and de-encapsulates PDUs, it scans for and performs handover to neighboring networks, and if appropriate, it consumes MAC management messages received from the base stations of the networks.

Fig. 5 is a flow diagram of an example embodiment of a network handover method for handover between multiple networks. In the embodiment depicted in fig. 5, the subscriber station uses a separate modem to switch between the two networks, where the first network is a bi-directional network and the second network is a unidirectional network, as in the system described above with respect to fig. 1-4. Of course, the present invention is also applicable to various other unidirectional networks and/or combinations of bidirectional networks. In the embodiment shown in FIG. 5, it may be described as a "special mode" flow beginning at block 501. Flow continues to block 502 and the subscriber station connects and associates itself to the bi-directional network. In one embodiment, the first network may be a bi-directional network 12. When the subscriber station 10 is connected to a bidirectional network, network state information of the bidirectional network may be stored and periodically updated. In one embodiment, the bidirectional network may be a bidirectional WiMAX network.

Flow continues to block 503. The subscriber station 10 retrieves network state information about the unidirectional network, such as DVB-H in the aforementioned WiMAX broadcast unidirectional network, in block 503. The retrieved information may include network state information for the unidirectional network, as well as content meta-information about events of interest and event timing in the unidirectional network. In one embodiment, the subscriber station 10 retrieves information from a bidirectional network regarding a unidirectional network. In another embodiment, the subscriber station 10 retrieves information about the unidirectional network from the unidirectional network itself. Flow continues to block 504 and the subscriber station 10 remains connected to the bi-directional network and monitors or otherwise utilizes the services of the bi-directional network.

Flow continues to block 505 where it is determined whether an event is desired, such as a broadcast television program, to begin in the unidirectional network that subscriber station 10 desires to receive, for example, as indicated by the user selecting a content item from an Electronic Service Guide (ESG) displayed on subscriber station 10. For example, if there is a particular stream of desired content, a determination is made as to whether the particular content stream will be transmitted in the unidirectional network based on previously obtained content meta-information associated with the unidirectional network. If it is determined in block 505 that the expected event will not begin, then the flow returns to block 504 and the subscriber station continues to monitor the bi-directional network. If, at block 505, it is determined that the desired event is about to begin, flow continues to block 506 where the subscriber station 10 detaches itself from the bidirectional network. Although the subscriber station 10 is detached from the bidirectional network, the subscriber station 10 maintains its established association with the bidirectional network.

Flow continues to block 507 where the subscriber station 10 connects to a unidirectional network. Flow then continues to block 508 where the subscriber station 10 collects data regarding the desired event, such as video data in the MPEG-2TS packet format, while connected to the unidirectional network. Flow continues to block 509 where it is determined whether the event is expected to be done (complete). If it is determined in block 509 that the desired event has not been completed, flow returns to block 508 and the subscriber station 10 continues to collect more data regarding the desired event. In this manner, the subscriber station remains connected to the unidirectional network in a dedicated manner until all data for the desired event is collected. If it is determined in block 509 that the event is expected to be completed, then flow continues to block 510.

In block 510 the subscriber station 10 disconnects from the unidirectional network and the flow continues to block 511. In block 511, the subscriber station 10 reconnects to the bi-directional network to which an association has been established. The flow then continues to block 504 and the subscriber station 10 monitors the bi-directional network until such time as other desired events are to begin on the unidirectional network.

In one embodiment, the desired content "event" may be a broadcast, such as a video data stream. An event has a start time and a completion time and if the event data is interleaved, the two events can overlap in time. If the subscriber station 10 receives two or more events, the end of one event does not necessarily mean that the other events have ended. In one embodiment, the event has a duty cycle with a cycle value between 1 and 100. If time slicing (interleaving of content data) is not used in a unidirectional network, the duty cycle of the events is 100 and there cannot be an overlap between events. If the temporal duty cycle is less than 100, then the time slice will be used. In one embodiment, events are transmitted continuously over a unidirectional network.

Fig. 6 is a network switch timeline in accordance with an example embodiment. In the embodiment illustrated in fig. 6, the unidirectional network transmits interleaved event packets of three events 73, 74 and 75, which are selected for download at the subscriber station 10. Each of the events 73, 74 and 75 comprises a series of time slices of packets 77, 78 and 79 with appropriate headers identifying the events, separated by time slices 93 during which time slices 93 the desired event was not transmitted, as illustrated by an event in fig. 7. As shown in fig. 7, event 73 includes time slicing 77 of event data packets of transmitted event 73, where event data time slicing 77 is isolated by time slicing 93 when data packets associated with event 73 are not transmitted. During the time slicing 93 of the event 73, the data packets of the other events may be transmitted in an interleaved manner, as depicted by the three events 73, 74 and 75 in fig. 6.

When the subscriber station 10 is connected to one of the two networks, the subscriber station 10 collects content meta-information for one or more desired events. For example, when the subscriber station 10 is connected to a bi-directional network, the subscriber station 10 may collect content meta-information regarding one or more events that are to occur on the unidirectional network, as described above in FIG. 3B.

In a mode referred to as the dedicated mode, the subscriber station 10 remains connected to the unidirectional network as described above in fig. 5, and the desired event occurs on the unidirectional network until the desired event ends. For example, if the subscriber station schedules to receive the three events 73, 74 and 75 in fig. 6, the subscriber station 10 remains connected to the unidirectional network until the end of the last event, in this case event 75. In this example, when the last event, event 75, is complete, the subscriber station 10 detaches from the unidirectional network and reconnects to the bidirectional network and remains connected to the bidirectional network until a specified time before the next desired event of the unidirectional network begins, or until the subscriber station 10 disconnects or turns off power. In this dedicated mode embodiment, when a bi-directional network is present, the subscriber station 10 remains connected to the bi-directional network unless an expected event occurs in the unidirectional network, in which case the subscriber station 10 will connect to the unidirectional network and remain connected to the unidirectional network while receiving and collecting expected event data until the event is completed.

In one embodiment, when the subscriber station 10 is powered on and connected to a bi-directional network, the subscriber station 10 is configured to download Electronic Service Guide (ESG) information for unidirectional network content from an ESG server. When an ESG query is submitted to the ESG server, the subscriber station 10 may include a Base Station Identifier (BSID) of its serving base station on the bidirectional network. This may be used to identify the unidirectional network in which the subscriber station 10 is currently located. The ESG describes the events that are or will be available in the unidirectional network in which the subscriber station 10 is located. The subscriber station 10 may also download the relevant MPEG-2 program description information (PSI) table for the unidirectional network in which the subscriber station 10 is located during the same exchange over the bidirectional network. The MPEG-2PSI describes the parameters of the unidirectional network, describes the elementary streams present in the broadcast, and maps the IP address to the MPEG-2 Packet Identification (PID). In one embodiment, this information may be stored in the NAA data storage module 38 as part of the second network state information 42. The user may select a desired event for download from the ESG. The subscriber station 10 remains connected to the bi-directional network until the start of a desired event on the unidirectional network.

The ESG is obtained on an IP stream in the unidirectional network 14 and the MPEG-2PSI is obtained on well known elementary streams, and the subscriber station 10 may alternately obtain the ESG and PSI from these sources. However, obtaining this information via a bidirectional network may speed up the synchronization time when the subscriber station 10 connects to a unidirectional network. The subscriber station 10 knows the IP addresses of all desired events on the unidirectional network via the ESG and may use the mapping of IP addresses to program IDs provided in the PSI to find and filter the desired events. The ESG and MPEG-2PSI may also be transmitted at a low rate in a unidirectional network in the event that the subscriber station 10 enters the unidirectional network without first connecting to and associating with the bidirectional network. The format of the ESG is the same regardless of whether it is obtained through downloading or via a time slicing IP stream, and the ESG may be an extended markup language (XML) file with an easily understandable namespace.

If a bidirectional network is not present, either because it is not present or out of range or is lost when the subscriber station 10 connects, the subscriber station 10 searches for and connects to the unidirectional network by, for example, using the method of co-pending application No.11/6233,032 referenced above. Once connected to the unidirectional network, the subscriber station 10 searches, from time to time, for a bidirectional network that is orthogonal to the unidirectional network expected events, using standard methods of searching for, connecting to, and associating with bidirectional networks. The geographic location information provided by the unidirectional network may be used to narrow the search range of the bidirectional network.

Returning to fig. 6, during a specified time period prior to the expected event start period 82, but before the subscriber station detaches from the bidirectional network, the subscriber station 10 generates a query for network information associated with the unidirectional network on the bidirectional network, such as a unidirectional network Preferred Roaming List (PRL) query to a PRL server as in fig. 6, or a query to other servers for other available information about the unidirectional network, such as neighbor network information, etc. The BSID of the current serving base station in the bi-directional network may be included in the query in order to identify the unidirectional network in which the subscriber station 10 is located. The PRL query results in a download PRL71, which may be used to accelerate the one-way network search process. Prior to the first event start period 82, PRL71 is downloaded. After downloading PRL71, or after downloading other unidirectional network information via a bidirectional network, there is an idle signaling pattern 72. The subscriber station remains in the idle mode 72 until the network switching period 80 occurs. Network switching period 80 occurs a sufficient period of time 81 prior to first event start period 82 to allow subscriber station 10 sufficient time to connect to the unidirectional network. The subscriber station 10 will then collect the expected event data until all expected events are completed, at which point the next network switch period 83 occurs. In a time period 85 following the network switch period 83, the subscriber station 10 will be connected to the bidirectional network. After the subscriber station is connected to the bi-directional network, it enters the network and re-enters the signal period 76.

In one embodiment, if the subscriber station 10 is not already in idle mode when detaching itself from the bidirectional network, it sends a de-registration request (DREG-REQ) message to the base station of the bidirectional network, and the base station responds with a de-registration command DREG-CMD including paging parameters. These paging parameters are not associated with the subscriber station 10 at this point because the subscriber station 10 does not respond to a page when disconnected from and connected to a bidirectional network. However, from the perspective of a bi-directional network, it is not known whether the subscriber station 10 enters idle mode to save power or whether it enters idle mode to cause the subscriber station to switch networks, so the bi-directional network sends paging parameters as often. If the unidirectional network PRL was just downloaded to the subscriber station 10, the subscriber station 10 is likely not in idle mode. If the unidirectional network download PRL was not recently downloaded by the subscriber station 10, then it is likely that the subscriber station 10 is already in idle mode and may simply detach from the bidirectional network once the start of the desired event on the unidirectional network.

The process of searching for and connecting to a unidirectional network according to an embodiment is described in detail in the previously referenced U.S. patent application No.11/623,032. Using the ESG and PSI information, the subscriber station 10 receives and parses the desired event IP packets from the unidirectional network. The subscriber station may conserve power by instructing the receiver to "turn off" during time slices when expected event data packets are not being transmitted over the unidirectional network (i.e., when packets pertaining to an unexpected event arrive). If another overlapping expected event begins during the current expected event process, the subscriber station receives and collects all expected event data by adjusting the time-sliced duty cycle and receiving the appropriate IP packets for the expected event.

Both the ESG and the PRL may be retrieved using the simple file transfer protocol (TFTP). The subscriber station 10 obtains ESG and PRL information from an ESG and PRL server having an IP address that may be known to the subscriber station. Alternatively, the IP address is received by domain name system query (DNS) or ESG/PRL query means from the subscriber station via a bi-directional network.

At the end of the expected event, the subscriber station 10 detaches itself from the unidirectional network and connects to the bidirectional network again, as shown in fig. 6, if there are no more expected events in progress. When reconnecting to the bi-directional network, the subscriber station 10 follows the defined operation of transitioning from idle mode to normal mode. For example, the procedure may include a ranging request/ranging response (RNG-REQ/RNG-RSP) exchange between the subscriber station 10 and a bidirectional network base station.

The frequency with which the ESG is downloaded to the subscriber station 10 depends on the dynamic nature of the broadcast network planning, the extent to which the ESG is mapped into the future, and on the mobility of the subscriber station 10. When connected to a bi-directional network, if the subscriber station 10 roams to a new unidirectional network, the subscriber station 10 downloads the ESG and PSI for the new unidirectional network. The subscriber station 10 recognizes that it is a new unidirectional network by the BSID of the new serving base station in the bidirectional network. The subscriber station 10 may use a mapping table or received data, or other suitable method, to associate the BSID of the bi-directional network to the associated unidirectional network. The new BSIDs for the bi-directional network and the unidirectional network may be stored in the first network state information 40 and the second network state information 42 of the data storage module 38. Before the start of a new event, the subscriber station 10 only downloads the unidirectional network PRL when the serving BSID of the bidirectional network changes.

In one embodiment, to facilitate a dedicated mode of collecting desired event data as described above, an idle mode 72, as defined by IEEE802.16 e, may be used. The subscriber station enters idle mode 72 by sending a MAC management message to the base station of the bi-directional network and then receiving an acknowledgement containing the paging group to which the subscriber station belongs and other related paging information. The idle mode 72 may be used when an event is expected to occur in a unidirectional network (where the subscriber station is detached from the bidirectional network) or when the subscriber station wants to save power but is not detached from the bidirectional network.

When entering idle mode 72 in the two-way network for power saving purposes, the subscriber station wakes up during its page listening and responds to all pages in the two-way network. The subscriber station also transmits a location update message within its idle mode timing. When entering idle mode 72 for the purpose of receiving a desired event in the unidirectional network, the subscriber station does not attempt to reconnect to the bidirectional network to page for listening or to transmit a location update message.

When a subscriber station is associated with a base station serving a bidirectional network, it indicates that it is a broadcast capable device, indicating to the base station that the logical connection should not be torn down or the association registered even if the subscriber station is detached from the bidirectional network. The subscriber station may indicate that it is broadcast capable in any suitable manner, such as by way of a Type Length Value (TLV) within a basic capacity exchange during establishment of an association with the bi-directional network. When the subscriber station detaches from the bidirectional network and connects to the unidirectional network, it does not respond to the page or send a periodic location update message on the bidirectional network. When the idle mode system timing is exhausted or the paging retry count of the bidirectional network serving base station decreases to zero (i.e., the subscriber station does not respond to the page), the subscriber station's associated service and operational information reserved for base station idle mode management purposes is discarded, but the subscriber station does not discard its associated data or disconnect from the bidirectional network. A meta-timer may be provided at the base station of the bi-directional network, which may be on the order of tens of minutes to hours, in the case of a subscriber station separated from the bi-directional network for a long period of time. When the meta-timer expires, the subscriber station disconnects from the bidirectional network.

Fig. 8 illustrates another embodiment in which a switching pattern or method is used to switch between two networks, such as between a bi-directional network and a unidirectional network, to receive a desired event broadcast over the unidirectional network. In one embodiment, the subscriber station switches between the unidirectional network and the bidirectional network during one or more desired events, rather than attempting to remain connected to the unidirectional network for the entire duration of the desired event. DVB-H over a unidirectional network to broadcast multimedia content is implemented in one embodiment, with switching patterns made possible by DVB-H time slicing. In this switching mode, the time period during which the subscriber station is detached from the bidirectional network is much shorter than the dedicated mode time period described above with reference to fig. 5. In the embodiment illustrated in fig. 8, the user switches between two networks, the first being a bidirectional network and the second being a unidirectional network. Of course, the embodiment of the invention described in fig. 8 may also be implemented by other combinations of unidirectional and/or bidirectional networks.

The flow of fig. 8 begins at block 801. Flow then continues to block 802 where the subscriber station is connected to and associated with a bi-directional network. Flow then continues to block 803 where information about the unidirectional network is retrieved, as well as information corresponding to the desired event selected in the unidirectional network. In one embodiment, the subscriber station retrieves this information in block 803 via a bidirectional network. The retrieved information may include network state information of the unidirectional network, including parameters related to the unidirectional network, as well as content meta-information about the event, and timing of the event. In another embodiment, the subscriber station 10 retrieves information about the unidirectional network from the unidirectional network itself, collects the information after connecting to the unidirectional network in block 803.

In one embodiment, the subscriber station retrieves information about the unidirectional network and the desired event, such as information about a content program selected from an Electronic Service Guide (ESG) obtained from the user input and displayed by the subscriber station, in block 803. In one embodiment, a subscriber station connects to a unidirectional network and retrieves program information transmitted at a low rate over the unidirectional network. In another embodiment, the subscriber station retrieves program information on the bidirectional network, such as using the content meta-information module 53 of fig. 4. In one embodiment, the subscriber station apparatus presents program information to the user, such as in the form of an ESG, that indicates to the subscriber station a desired event.

Flow continues to block 804 where the subscriber station 10 remains connected to and monitoring the bi-directional network. When monitoring the bi-directional network, the subscriber station may disconnect from and reconnect to the bi-directional network at intervals, for example, due to entering a sleep mode for power saving.

Flow continues to block 805 where it is determined whether the desired event is to begin on the unidirectional network. For example, if there is a particular content stream associated with a program that the user of subscriber station 10 wants to receive, it determines whether the particular content stream will be transmitted over a unidirectional network. If it is determined that the expected event will not begin on the unidirectional network, the flow returns to block 804 and the subscriber station continues to monitor the bidirectional network. If, in block 805, it is determined that the desired event is to begin, flow continues to block 806.

In block 806, it is determined whether the desired time slice of event data is to begin within the desired event of the unidirectional network. If it is expected that the time slice will not start, flow remains at block 805. If, in block 805, it is determined that an event slice is expected to begin, flow continues to block 807. Referring to fig. 7, the data of event 73 is divided into time slices 77, in which portions of the event data are transmitted. Event data time slices 77 are separated by time slices 93, with no event data transmission for events 73 at time slices 93. If it is desired to receive the event 73 shown in FIG. 7, then in block 806 it is determined whether it is desired that the event time slice 77 be about to begin. If it is desired that the event time slice 77 be started, flow continues to block 807.

In block 807, the subscriber station is detached from the bidirectional network but remains associated with the bidirectional network. Flow continues to block 808 and the subscriber station connects with the unidirectional network. Flow continues to block 809 and event time-slice data is collected during transmission of the desired event time-slices from the unidirectional network. Flow then continues to block 810 where it is determined whether time slicing completion is desired. If the desired time-slice is not complete, flow returns to block 809 and more desired event time-slice data is collected. If, in block 810, it is determined that the event timeslice is expected to be completed, flow continues to block 811. Referring to fig. 7, if the subscriber station receives data from the first time-slicing event 77, the subscriber station determines whether the first time-slicing event 77 is completed in block 810. If it is determined that the first time-slice event 77 is not complete, meaning that no more data is received in the time slice, the user station continues to receive the desired event data in block 809. If it is determined that the desired time-slice event 77 is complete, meaning that no more event data associated with the desired event is to be transmitted until the next event time-slice 77 begins (after the interval time-slice 93), then flow continues to block 811.

At block 811, the subscriber station detaches from the unidirectional network. Flow continues to block 812 and the subscriber station connects to the bi-directional network with which it has established an association. Flow then continues to block 813 where it is determined whether the event is complete. In other words, it determines whether all of the desired data associated with the desired event has been collected. If, in block 813, it is determined that the event is not complete, then flow returns to block 806 and the user station waits for the next expected event time slice to occur. Returning to block 813, if it is determined that the event is complete, flow continues to block 804 and the subscriber station monitors the bi-directional network until such time that the next desired event is to begin on the unidirectional network.

Referring to FIG. 6, if it is determined in block 813 that the desired event, e.g., first event 73, is not complete, meaning that data still associated with the first event is not collected, then flow continues to block 806 and the user station waits for the next time slice of the first event 73, e.g., time slice 77 of FIG. 7. If, in block 813, it is determined that an expected event, such as the first event 73, is complete, then the flow returns to block 804 and the subscriber station waits for the next expected event.

The switched mode technique depicted in fig. 8 allows a subscriber station to connect to a unidirectional network in proportion to the expected events received and the number of duty cycles for those events, based on time slicing interleaved with event data transmitted by the unidirectional network. The subscriber station may reconnect itself to the bidirectional network during the expected event interval when the undesired event data is transmitted. In one embodiment these intervals are on the order of seconds. This means that during a time slice of the transmission of a desired event data packet, for example, a subscriber station may connect to a unidirectional network and receive a desired MPEG-2 multimedia transport stream data packet, for example, a video stream. When a time slice occurs in which the expected event data packet is not transmitted, the subscriber station connects to a different network, such as a bi-directional network. In one embodiment, the subscriber station "halts" itself in the bidirectional network when no event is received. In the handoff mode, the subscriber station's modem quickly connects itself to the relevant network to accommodate the time slice interval limitation. For example, the connection to the network may include tuning the modem to the network frequency, having the modem locate, search for and find a frame preamble (e.g., in a standard IEEE802.16 e frame), and obtaining frame synchronization, i.e., Frame Control Header (FCH) and downlink and uplink map reception. This connection to the network may occur within a few Time Division Duplex (TDD) frames of the unidirectional network.

In one embodiment, when the subscriber station switches networks using time slicing, as in fig. 8, it interprets the IP flow from the unidirectional network and parses the timing and other necessary information to complete the time slicing from the headers that encapsulate the IP packets in the IP flow. This information tells the receiver when the current time slice or expected event content data packet ends and when the next time slice of the expected event content begins. Knowing the start and end times of the desired event time slice allows the subscriber station to keep its modem connected to the unidirectional network to transmit event data until the current desired event slice is complete, and then connect the modem to another network to take advantage of traffic on that other network until the next desired event time slice on the unidirectional network begins.

In the above embodiments, the RF modem handles switching back and forth between two networks, such as a unidirectional network on one frequency and a bidirectional network on the other frequency. In one embodiment, the subscriber station is capable of receiving broadcast multimedia data, such as video streams, from a unidirectional network and engaging in bidirectional communications with other networks, such as IP-based services with other networks, using the handoff techniques and methods described herein. A user, such as a personal media player, a cell phone, a portable digital assistant, a portable computer, etc., implemented by a subscriber station in the previously described system is able to receive content, such as multimedia content, e.g., video, using a bi-directional network, and is also able to subscribe to services provided over a unidirectional network using an uplink bi-directional network, as well as to subscribe to the use of traditional voice services or other bi-directional services.

Those of skill in the art will understand that the various illustrative modules and method steps described in connection with the figures described above, and the embodiments disclosed herein can generally be implemented in electronic hardware, software, firmware, or combinations of these. To clearly illustrate this alternation of hardware and software, various illustrative modules and method steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the desired functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention. Further, the grouping of functions in modules or steps is for ease of description. Specific functions can be transferred from one module or step to another without departing from the scope of the invention.

Moreover, the various illustrative modules and method steps described in connection with the embodiments disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor ("DSP"), an application specific integrated circuit ("ASIC"), a programmable gate array ("FPGA") or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other similar configuration.

Furthermore, the steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module can reside in RAM memory, FLASH memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium, including a network storage medium. An exemplary storage medium can be coupled to the processor such the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium can also reside in an ASIC.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles described herein may be applied to other embodiments without departing from the spirit or scope of the invention. It is therefore to be understood that the description and drawings presented herein represent exemplary embodiments of the invention and are therefore representative of the subject matter which is broadly contemplated by the present invention. It is further to be understood that the scope of the present invention fully encompasses other embodiments and therefore is intended to be limited by the scope of the appended claims.

Claims

1. A method for operating a wireless communication device that communicates with at least two different wireless networks using a single radio frequency modem, comprising:

connecting a wireless device to a first wireless network through a Radio Frequency (RF) modem;

disconnecting the wireless device from the first wireless network at a predetermined time that is before a start time of a selected event in the second wireless network;

connecting the wireless device to a second wireless network using the same RF modem prior to the start time of the selected event;

collecting at least a portion of event data associated with a selected event at the wireless device, the selected event transmitted from the second wireless network after a start time of the selected event;

disconnecting the wireless device from the second wireless network after at least a portion of the event data is collected in the collecting step; and

the wireless device is reconnected to the first wireless network after disconnecting from the second wireless network.

2. The method of claim 1, wherein in the collecting step, all of the event data is collected before the wireless device in the disconnecting step disconnects from the second wireless network.

3. The method of claim 1, wherein the collecting step further comprises:

collecting a plurality of contiguous data packets from an aggregate data stream of interleaved time slices associated with one or more events during each of a plurality of time slices associated with a selected event;

disconnecting the wireless device from the second wireless network and reconnecting the wireless device to the first wireless network during at least one time slice not associated with the selected event; and

the wireless device is disconnected from the first wireless network and reconnected to the second wireless network at a predetermined time that is before the start time of the next time slice associated with the selected event.

4. The method of claim 3, wherein in the collecting step, a plurality of consecutive data packets are collected during each of a plurality of time slices associated with each of a plurality of selected events, and the wireless device is connected to the first wireless network during a time slice not associated with any of the plurality of selected events.

5. The method of claim 3, further comprising transmitting time-slice timing information from an upper layer application module in the wireless device to a Media Access Control (MAC) module in the RF modem, wherein the MAC module controls the timing of the collecting and disconnecting steps in accordance with the time-slice timing information.

6. The method of claim 1, wherein the first wireless network is a two-way wireless network and the second wireless network is a one-way broadcast wireless network.

7. The method of claim 1, wherein at least one of the at least two wireless networks is a broadband wireless network.

8. The method of claim 1, wherein at least one of the at least two wireless networks is a unidirectional broadcast network.

9. The method of claim 1, wherein the steps of connecting and reconnecting to the first wireless network include providing first network state information stored in the wireless device to the RF modem and using the first network state information to facilitate communication with the first wireless network.

10. The method of claim 9, wherein the step of connecting to the second wireless network comprises providing second network status information stored in the wireless device to the RF modem and using the second network status information to facilitate communication with the second wireless network.

11. The method of claim 10, wherein each of the stored first and second network state information comprises at least one of a network frequency, a Base Station Identifier (BSID), a Connection Identifier (CID), and waveform timing information for the respective network.

12. The method of claim 1, wherein at least two wireless networks operate at different network frequencies, and the network frequencies are stored by the wireless device and used by the RF modem to tune to respective wireless network frequencies when connected to respective ones of the first and second wireless networks.

13. The method of claim 1, further comprising downloading and storing Electronic Service Guide (ESG) information associated with the second network from an ESG server in the wireless device while the wireless device is connected to the first network.

14. The method of claim 13, wherein downloading and storing ESG information further comprises transmitting an ESG query from the wireless device to an ESG server.

15. The method of claim 14, wherein the ESG query includes a Base Station Identifier (BSID) of a base station of the first wireless network currently serving the wireless device.

16. The method of claim 13, further comprising receiving a user input corresponding to at least one selected event of the plurality of events identified in the ESG information, storing event timing information for the at least one selected event, and connecting to a second network at a predetermined time using the selected event timing information to collect event data associated with the at least one selected event.

17. The method of claim 1, further comprising re-establishing paging and location parameters for wireless devices connected to the first wireless network each time the wireless device re-connects to the first wireless network.

18. The method of claim 1, further comprising sending a Preferred Roaming List (PRL) query to a PRL server associated with the second wireless network prior to disconnecting from the first wireless network, receiving a PRL associated with the second network from the PRL server, and using network information in the PRL to facilitate connecting to the second network.

19. The method as in claim 18, wherein the PRL query includes a Base Station Identifier (BSID) of a base station of the first wireless network currently serving the wireless device.

20. The method of claim 1, wherein the second wireless network is a unidirectional broadcast wireless network including at least one base station that transmits Orthogonal Frequency Division Multiplexed (OFDM) signals.

21. The method of claim 1, wherein the event data is transmitted from a base station in the second wireless network and comprises digitized video data conforming to a standard protocol.

22. A wireless communication device for operating in at least two different wireless networks, comprising:

a Radio Frequency (RF) modem configured to connect to a first wireless network and a second wireless network;

a network connection arbiter module configured to store timing information of event data bursts associated with selected events of the second wireless network, and to control the RF modem to connect to the first wireless network when data bursts associated with the selected events do not occur, and to control the RF modem to connect to the second wireless network when data bursts associated with the selected events occur; and

an application module collects at least a portion of the event data by collecting event data from the event data bursts associated with the selected event while the RF modem is connected to the second wireless network.

23. The wireless communication device of claim 22, wherein the application module collects all event data and then the RF modem disconnects from the second wireless network.

24. The wireless communication device of claim 22, wherein the application module collects the event data by collecting a plurality of consecutive data packets in an aggregate data stream of interleaved time slices associated with the one or more events by a person during each of the plurality of time slices associated with the selected event, wherein the network connection arbiter module controls the RF modem to disconnect from the second wireless network and reconnect to the first wireless network during at least one time slice not associated with the selected event, and wherein the network connection arbiter module controls the RF modem to disconnect from the first wireless network and reconnect to the second wireless network at a predetermined time before a start time of a next time slice associated with the selected event.

25. The wireless communication device of claim 24, wherein the application module collects a plurality of consecutive data packets during each of a plurality of time slices associated with each of a plurality of selected events, and wherein the network connection arbiter module controls the RF modem to connect to the first wireless network during a time slice not associated with any of the plurality of selected events.

26. The wireless communication device of claim 24, wherein time-slice timing information is sent from the application module to a network connection arbiter module that controls timing of the RF modem to the first and second wireless network connections in accordance with the time-slice timing information.

27. The wireless communication device of claim 22, wherein the first wireless network is a two-way wireless network and the second wireless network is a one-way broadcast wireless network.

28. The wireless communication device of claim 22, wherein at least one of the at least two wireless networks is a broadband wireless network.

29. The wireless communication device of claim 22, wherein at least one of the at least two wireless networks is a unidirectional broadcast wireless network.

30. The wireless communication device of claim 22, wherein the network connection arbiter module controls the RF modem to connect to the first wireless network by providing the first network status information to the RF modem, the RF modem using the first network status information to facilitate communication with the first wireless network.

31. The wireless communication device of claim 30, wherein the network connection arbiter module controls the RF modem to connect to the second wireless network by providing the second network status information to the RF modem, the RF modem using the second network status information to facilitate communication with the second wireless network.

32. The wireless communications apparatus of claim 31, wherein each of the first network state information and the second network state information includes at least one of a network frequency, a Base Station Identifier (BSID), a Connection Identifier (CID), and waveform timing information for the respective network.

33. The wireless communication device of claim 22, wherein at least two wireless networks operate in different network frequencies, and the network frequencies are stored by the wireless communication device and provided to the RF modem to tune the RF modem to a respective wireless network frequency when connected to a respective one of the first and second wireless networks.

34. The wireless communication device of claim 22, wherein at least two wireless networks operate in orthogonal codes that are stored in the wireless communication device and used to facilitate connecting the wireless device to respective ones of the first and second wireless networks.

35. The wireless communication device of claim 22, wherein the application module downloads Electronic Service Guide (ESG) information associated with the second network from an ESG server and stores in the memory when the wireless communication device is connected to the first wireless network.

36. The wireless communication device of claim 35, wherein the downloading of the ESG information is in response to an ESG query sent by the application module to an ESG server over the first wireless network.

37. The wireless communication device of claim 36, wherein the ESG query includes a Base Station Identifier (BSID) of a base station of the first wireless network currently serving the wireless communication device.

38. The wireless communication device of claim 35, wherein the application module receives user input corresponding to at least one selected event of the plurality of events identified in the ESG information, stores event timing information for the at least one selected event, and sends the event timing information to the network connection arbiter module, which uses the event timing information to control the RF modem to connect to the second network at a predetermined time to collect event data associated with the at least one selected event.

39. The wireless communication device of claim 22, wherein the RF modem establishes paging and location parameters for the wireless communication device connected to the first wireless network each time the RF modem connects to the first wireless network.

40. The wireless communication device of claim 22, wherein the application module sends a Preferred Roaming List (PRL) query to a PRL server associated with the second wireless network before disconnecting from the first wireless network, receives a PRL associated with the second network from the PRL server, and sends network information in the PRL to the network connection arbitrator module, which uses the network information to control the RF modem to facilitate connecting to the second network.

41. The wireless communication device of claim 40, wherein the PRL query includes a Base Station Identifier (BSID) of a base station of the first wireless network currently serving the wireless communication device.

42. The wireless communication device of claim 22, wherein the second wireless network is a unidirectional broadcast wireless network including at least one base station that transmits Orthogonal Frequency Division Multiplexed (OFDM) signals.

43. The wireless communication device of claim 22, wherein the event data is transmitted from a base station in the second wireless network and comprises digitized video data conforming to a standard protocol.

44. One or more processor-accessible media comprising processor-executable instructions that, when executed, instruct a wireless device to perform operations comprising:

45. A method of operating a communication device to communicate with at least two different networks using a single modem, the method comprising:

establishing a first connection with a first wireless network through a modem;

receiving second network state information associated with a second wireless network through a first connection with a first wireless network; and

a second connection is established with a second wireless network through the modem using second network status information.

46. The method of claim 45, further comprising storing second network state information associated with a second wireless network; and storing first network state information associated with the first wireless network and re-establishing the first connection with the first wireless network using the first network state information.

47. The method of claim 45, further comprising reestablishing communication with the second wireless network using the second network state information at a predetermined time, the predetermined time prior to the beginning of the second wireless network selection event.

48. The method of claim 47, further comprising collecting, in the communication device, at least a predetermined portion of the event data from the second network during a selected event in the second network, and then reestablishing the first connection with the first wireless network using the first network state information.

49. A method as defined in claim 46, further comprising upgrading the stored first network state information each time the communication device connects to the first wireless network and upgrading the stored second network state information each time the communication device connects to the second wireless network.

50. The method of claim 45, wherein the first wireless network is a directional network and the second wireless network is a unidirectional broadcast network.

51. The method of claim 45, wherein at least a portion of the second network status information is received from an Electronic Service Guide (ESG) server over the first connection, and the second network status information comprises ESG information associated with a plurality of events scheduled for transmission on the second wireless network.

52. The method of claim 45, wherein the second network state information is received from the server over the first connection and the information includes at least one of a second network frequency, a Base Station Identifier (BSID), a Connection Identifier (CID), and waveform timing information associated with the second wireless network.

53. The method of claim 45, wherein the second network status information is received from the server over the first connection and includes Program Specific Information (PSI) that maps the data address information to each of a plurality of events scheduled for transmission on the second wireless network.

54. A wireless communication device for communicating over at least two wireless networks, comprising:

a Radio Frequency (RF) modem;

a network connection arbiter module connected to the RF modem and controlling the RF modem to establish a first connection with a first wireless network and to establish a second connection with a second wireless network on an alternating basis; and

an application module connected to the RF modem and the network connection arbiter module and receiving second network status information associated with the second wireless network through the first connection with the first wireless network and transmitting the second network status information to the RF modem for establishing a second connection with the second wireless network.

55. The wireless communication device of claim 54, wherein the application module stores second network state information associated with the second wireless network and stores first network state information associated with the first wireless network, and wherein the network connection arbiter module controls the RF modem to re-establish the first connection with the first wireless network using the first network state information.

56. The wireless communication device of claim 55, wherein the network connection arbiter module controls the RF modem to re-establish the second connection with the second wireless network using the second network state information at a predetermined time prior to a beginning of a selected event in the second wireless network.

57. The wireless communication device of claim 56, wherein the application module collects at least a predetermined portion of the event data from the second network during the selected event in the second network.

58. The wireless communication device of claim 55, wherein the application module upgrades the stored first network state information each time the communication device connects to the first wireless network, and the application module upgrades the stored second network state information each time the communication device connects to the second wireless network.

59. The wireless communication device of claim 54, wherein the first wireless network is a two-way network and the second wireless network is a one-way broadcast network.

60. The wireless communication device of claim 54, wherein at least a portion of the second network status information is received from an Electronic Service Guide (ESG) server over the first connection, and the second network status information comprises ESG information associated with a plurality of events scheduled for transmission on the second wireless network.

61. The wireless communication device of claim 54, wherein the second network state information is received from the server over the first connection and the second network state information includes at least one of a second network frequency, a Base Station Identifier (BSID), a Connection Identifier (CID), and waveform timing information associated with the second wireless network.

62. The wireless communication device of claim 54, wherein the second network status information is received from the server over the first connection and includes Program Specific Information (PSI) that maps data address information to each of a plurality of events scheduled for transmission on the second wireless network.

63. One or more processor-accessible media comprising processor-executable instructions that, when executed, instruct a wireless device to perform operations comprising:

establishing a first connection with a first wireless network through a modem;

64. A multiple network system comprising:

a first wireless network having a plurality of base stations;

a second wireless network having a plurality of base stations; and

the at least one wireless communication device includes:

65. The system of claim 64 wherein the wireless communication device is a subscriber station.

66. The system of claim 65, wherein the user station is one of a personal media player, a cell phone, a personal digital assistant, or a computer.

67. The system of claim 64, wherein the first wireless network is a two-way network.

68. The system of claim 64, wherein the second wireless network is a one-way broadcast network.