Replies to post #259979 on InterDigital Inc (IDCC)

[Gamco]

United States Patent 7,545,778
Sugar , et al. June 9, 2009

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Apparatus for antenna diversity using joint maximal ratio combining


Abstract
A transceiver using composite beamforming technique is provided wherein a first communication device has a plurality of antennas and the second communication has a plurality of antennas. When the first communication device transmits to the second communication device, the transmit signal is multiplied by a transmit weight vector for transmission by each the plurality of antennas and the transmit signals are received by the plurality of antennas at the second communication device. The optimum transmit weight vector and receive weight vector for communication between the first and second communication devices is determined so that there is effectively joint or composite beamforming between the communication devices.


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Inventors: Sugar; Gary L. (Rockville, MD), Vaidyanathan; Chandra (Bethesda, MD), Tesfai; Yohannes (Falls Church, VA)
Assignee: IPR Licensing, Inc. (Wilmington, DE)

Appl. No.: 11/231,161
Filed: September 20, 2005

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Related U.S. Patent Documents

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Application Number Filing Date Patent Number Issue Date
10695229 Oct., 2003 6965762
10174728 Feb., 2004 6687492
60365797 Mar., 2002
60361055 Mar., 2002


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Current U.S. Class: 370/335 ; 342/372; 370/334; 370/342; 375/148; 455/276.1
Current International Class: H04B 7/216 (20060101)
Field of Search: 370/329,331,332,334,335,342 375/148 342/372 455/276.1

[dndodd]

Gamco,

Thanks for your continued efforts in always posting IDCC's new patents here.

David

[revlis]

United States Patent 7,545,780
Chitrapu June 9, 2009
Flow-based selective reverse tunneling in wireless local area network (WLAN)-cellular systems


Filed: November 14, 2002

BACKGROUND

This invention generally relates to interconnected systems of wireless local area networks (WLANs) and cellular networks. In particular, the invention relates to routing packets within such systems.

Mobile IP versions 4 (MobileIPv4) and 6 (MobileIPv6) provide solutions to this problem. In MobileIPv4,the subscriber informs the cellular gateway router of its new location. These additional functions of the cellular gateway router and the WLAN-AR are referred to as Home Agent and Foreign Agent functions. When the cellular gateway router 36 receives the subscriber's packets from the desired node 38, the router 36 forwards them to the WLAN-AR 26. The WLAN-AR 26 sends the packets to the IP address of the subscriber 20 using layer 2 address mapping procedures, such as ARP.

A drawback with this approach is that packets originating from the subscriber 20 going through the WLAN 22 are not visible to the cellular network 30 or router 36. Another drawback with this approach is the increased loading on the cellular gateway router 36, due to the routing of all the subscriber's incoming packets.

In MobileIPv6,the subscriber 20 sends a binding update to the cellular gateway router 36 and the desired node 38. The binding update has information about the new network (WLAN 22) that the subscriber 20 is attached to. The IP packets from the destination node 38 are now routed directly to the subscriber 20 bypassing the cellular gateway router 36 and using standard IP routing protocols. A drawback with this approach is that packets originating from and going to the subscriber are not visible to the cellular network.

In some cases, it is undesirable that the IP packets are not visible to the cellular network 30. One reason is the security protocols of the cellular system 30 are circumvented. Additionally, certain services of the cellular system 30 can not be utilized, such as access to the cellular network's packet services.

To allow all of the subscriber packets to be visible to the cellular network 30, reverse and/or forward tunneling can be used. As shown in FIG. 2, in reverse tunneling, the packets from the subscriber 20 in the WLAN 22 are routed through both the WLAN 22 and the cellular network 30. Packets are transferred between the routers (cellular gateway router 36 and WLAN-AR 26) via an IP network 29. Reverse tunneling is supported by Mobile IPv4 and it allows all of the packets to be visible to the cellular network 30.

For MobileIPv6,both forward and reverse tunneling are needed to make the packets visible to the cellular network 30. In forward tunneling, the packets are also routed through both the cellular network 30 and the WLAN 22.

By routing all the packets through the cellular gateway router 36, the cellular system 30 can maintain security and provide cellular network based packet services to the subscriber 20, even when located in WLAN 22. To illustrate, the cellular gateway router 36 may send packets to a screening/monitoring agent for security purposes. One drawback to both these approaches is that the loading on the cellular gateway router is increased.

To reduce the routing on the cellular gateway router 36, selective reverse tunneling may be used. In selective reverse tunneling, packets are either selectively routed through both the cellular network 30 and the WLAN 22 or only through the WLAN 22, on a packet by packet basis. Such packet by packet routing is undesirable, since it increases the processing load. Furthermore, such packet level granularity may not be needed for most applications.

Accordingly, it is desirable to have alternate approaches to cellular network and WLAN routing.

http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7,545,780.PN.&OS=PN/7,545,780&RS=PN/7,545,780