METHOD AND SYSTEM FOR SOFT HANDOFF IN MOBILE BROADBAND SYSTEMS

• US 20110235618A1
• Filed: 06/10/2011
• Published: 09/29/2011
• Est. Priority Date: 06/04/2004
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: TONG, Wen, SENARATH, Nimal, GAGE, Bill, PERIYALWAR, Shalini
• Granted Patent: US 8,442,009 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 36/20 for optimising the interference level
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 80/02 Data link layer protocols

Abstract

The present invention provides a method and system for facilitating efficient handoff and data throughput in mobile broadband communication systems. Methods implemented by a system constructed in accordance with the principles of the present invention include selectively enabled soft handoff, performing Layer 2 bearer functions at the base station and using the mobile device to coordinate soft handoff and interference avoidance without the need for a centralized coordination function.

Claims

1. A processing method for communication from a mobile device in a first network to a destination device in a second network using soft handoff in a mobile broadband system, the method comprising:

a) determining an active set of base station transceiver systems;

b) determining resource reservation at the macrodiversity support function for the base station transceiver systems in the active set of base station transceiver systems for communication of a high level data communication packet;

c) transmitting radio link protocol packets comprising the full high level data communication packet to the base station transceivers in the active set based on the determined resource reservations;

d) forwarding the full high level data communication packet to a macrodiversity support function; and

e) repeating steps (a) through (d) for all high level data communication packets to be transmitted.

2. The method according to claim 1, wherein the high level data communication packet is an Internet Protocol packet.

3. The method according to claim 1, wherein each high level data communication packet is assigned a sequence number by the mobile device, the method further comprising:

reordering the high level packets into sequential order based on the assigned sequence number; and

transmitting the high level packet to the second network for delivery to a destination device.

4. A data packet processing method for communication to a mobile device in a first network from a destination device in a second network using soft handoff in a mobile broadband system, the method comprising:

determining an active set of base station transceiver systems;

segmenting each of the data packets to be transmitted to the mobile device into radio link protocol packets based on a predetermined segmentation algorithm;

determining a synchronized transmission resource reservation for the radio link protocol packets and providing the resource reservation to all base station transceiver systems in the active set;

transmitting the data packet to each of the base station transceiver systems in the active set; and

transmitting each of the radio link protocol packets to the mobile device based on the transmission schedule using soft handoff.

5. The method according to claim 4, wherein the data packet is an Internet Protocol packet.

6. The method according to claim 4, further comprising, multiplexing non-soft handoff packets into unused explicit soft handoff scheduled assignments for transmission to the mobile device.

7. A mobile broadband system using soft handoff, the system comprising:

a plurality of base station transceiver systems;

a macrodiversity support function in data communication with the plurality of base station transceiver systems, the macrodiversity support function determining resource reservation for the base station transceiver systems in the active set of base station transceiver systems for communication of a high level data communication packet;

a mobile device arranged to engage in wireless communications with plurality of base station transceiver systems, the mobile device;

determining an active set of base station transceiver systems; and

transmitting radio link protocol packets comprising the full high level data communication packet to the base station transceivers in the active set based on the determined resource reservations, wherein the base station transceiver systems forward the full high level data communication packet to the macrodiversity support function.

8. The system according to claim 7, wherein the high level data communication packet is an Internet Protocol packet.

9. A mobile broadband system using soft handoff to facilitate transmission of a plurality of data packets, the system comprising:

a plurality of base station transceiver systems;

a mobile device arranged to engage in wireless communications with the plurality of base station transceiver systems, the mobile device;

determining an active set of base station transceiver systems; and

a macrodiversity support function in data communication with the plurality of base station transceiver systems, the macrodiversity support function;

determining a synchronized transmission resource reservation for radio link protocol packets comprising the data packet and providing the resource reservation to all base station transceiver systems in the active set; and

transmitting the data packet to each of the base station transceiver systems in the active set, wherein the base station transceiver systems in the active set segment the data packet into the radio link protocol packets based on a predetermined segmentation algorithm and transmit each of the radio link protocol packets to the mobile device based on the transmission schedule using soft handoff.