Wireless communication in multi-RAT system

• US 9,967,066 B2
• Filed: 02/11/2015
• Issued: 05/08/2018
• Est. Priority Date: 10/18/2012
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Li, Zhaojun, Moulsley, Timothy
• Primary Examiner(s): Harper, Kevin C
• Assistant Examiner(s): Rose, Derrick V
• Application Number:
  US14/619,498
• Publication Number:
  US 20150188681A1
• Time in Patent Office: 1,182 Days
• Field of Search: None
• CPC Class Codes: H04L 5/0032 Distributed allocation, i.e. involving a plurality of allocating devices, each making partial allocation
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 72/12 Wireless traffic scheduling
• CPC Class Codes: H04W 72/27 between access points
• CPC Class Codes: H04W 72/54 based on quality criteria
• CPC Class Codes: H04W 72/542 using measured or perceived quality
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: H04W 88/10 adapted for operation in multiple networks, e.g. multi-mode access points

Abstract

A scheme for the co-ordination of multiple base stations of different RATs (radio access technologies), such as a LTE eNB, UMTS base station, and WiFi access point with the assistance of the terminals in order to achieve efficient radio resource scheduling for multi-RAT multi-flow aggregation in the downlink. At the network side, multi-RAT flows (RB11) share the same PDCP Entity, (PDCP Entity) while each has independent RLC/MAC (RAT1 RLC Entity, RAT2 RLC Entity). The terminal (UE1) performs necessary measurements on all involved RATs, depending on the requirements of different RATs, and sends measurement reports/indication to all involved base stations. Based on the measurement report as well as pre-defined rules/policy, a decision is made on which RAT should be used for next DL transmission or next period of DL transmission.

Claims

1. A multi-RAT (radio access technologies) wireless communication system, comprising:

a terminal;

a first base station wirelessly communicating with the terminal via a first RAT; and

a second base station wirelessly communicating with the terminal via a second RAT;

the first and second RATs each having a Packet Data Control Protocol (PDCP) or equivalent layer as an upper protocol layer, and a Radio Link Control (RLC) or equivalent layer and a Media Access Control (MAC) or equivalent layer as lower protocol layers associated with the upper protocol layer;

the first and second base stations maintaining entities at each of a plurality of the protocol layers for configuring one or more radio bearers for wireless communication with the terminal; and

wherein the one or more radio bearers are carried by both the first and second RATs, a radio bearer being configured in the first and second base stations with a same entity at the PDCP or equivalent layer for the first and second RATs, and with different entities at one of the Radio Link Control (RLC) or equivalent, and the Media Access Control (MAC) or equivalent, protocol layers for the first and second RATs.

2. The wireless communication system according to claim 1, wherein the first and second base stations are provided by a single multi-RAT base station in which are provided a single entity per terminal at the PDCP or equivalent layer for both RATs and one or more different entities per terminal at the RLC or equivalent layer or at the MAC or equivalent layer for each RAT.

3. The wireless communication system according to claim 1, wherein the first and second base stations comprise physically separated base stations, in each of which are provided a single entity at the PDCP or equivalent layer for both RATs and one or more different entities at the RLC or equivalent layer or at the MAC or equivalent layer for each RAT, correspondence between respective entities in each base station being maintained by mutual communication via a communications link between the base stations.

4. The wireless communication system according to claim 3, wherein there is a single radio bearer, one of the base stations is selected as a primary base station responsible for management of the single radio bearer and for forwarding information to another base station.

5. The wireless communication system according to claim 1, wherein the first and second base stations comprise physically separated base stations each connected via a communications link to a central node, and in each of the base stations there are provided a single entity at the PDCP or equivalent layer for both RATs and one or more different entities at the RLC or equivalent layer or at the MAC or equivalent layer for each RAT, correspondence between respective entities in each base station being maintained by control of the central node.

6. The wireless communication system according to claim 1, wherein the radio bearer is applicable to both a downlink and an uplink, entities being defined at the RLC or equivalent layer or at the MAC or equivalent layer in each RAT for each of the uplink and downlink.

7. The wireless communication system according to claim 1, wherein the one or more radio bearers include a data bearer for serving the terminal with a given quality of service.

8. The wireless communication system according to claim 1, wherein one of the first and second base stations configures an additional radio bearer as a signalling bearer carried by only one of the RATs.

9. The wireless communication system according to claim 1, wherein uplink communication from the terminal is carried by only one of the RATs.

10. The wireless communication system according to claim 1, wherein the terminal is arranged to perform a measurement on a wireless communications link in at least one RAT and to send a measurement report via the at least one RAT.

11. The wireless communication system according to claim 10, wherein the measurement report contains information for more than one RAT.

12. The wireless communication system according to claim 10, wherein the measurement report contains an indication of a RAT preferred by the terminal for wireless communication with the terminal.

13. A method of operating a wireless communication system comprising:

a first base station wirelessly communicating with a terminal via a first RAT (radio access technologies); and

a second base station wirelessly communicating with the terminal via a second RAT;

providing the first and second RATs with Packet Data Control Protocol (PDCP) or equivalent layer as an upper protocol layer, and a Radio Link Control (RLC) or equivalent layer and a Media Access Control (MAC) or equivalent layer as lower protocol layers associated with the upper protocol layer;

maintaining, at the first and second base stations, entities at each of a plurality of the protocol layers for configuring one or more radio bearers for wireless communication with the terminal; and

carrying the one or more radio bearers by both the first and second RATs, the first and second base stations configuring a radio bearer with a same entity at the PDCP or equivalent layer for the first and second RATs, and with different entities at the RLC or equivalent layer or at the MAC or equivalent layer for the first and second RATs.

14. Base station equipment for use in a multi-RAT (radio access technologies) wireless communication system and providing at least one of a first base station wirelessly communicating with a terminal via a first RAT and a second base station wirelessly communicating with the terminal via a second RAT, the first and second RATs each defining a PDCP or equivalent layer as an upper protocol layer, and a Radio Link Control (RLC) or equivalent layer and a Media Access Control (MAC) layer or equivalent layer as lower protocol layers associated with the upper protocol layer;

wherein said base station equipment is arranged to maintain entities at each of a plurality of the protocol layers for configuring one or more radio bearers to be carried by both the first and second RATs for wireless communication with the terminal; and

the base station equipment being arranged to maintain a single entity per terminal at the PDCP or equivalent layer for the first and second RATs, and different entities per terminal at the RLC or equivalent layer or at the MAC or equivalent layer for the first and second RATs.