Method, base station, and communication network supporting High-Speed Uplink Packet Access (HSUPA) with soft handover mechanisms

Abstract

A method of supporting soft/softer handover mechanisms for High-Speed Uplink Packet Access (HSUPA) in a cellular communication network (1) with a plurality of base stations (2.1, 2.2), wherein said handover mechanisms include establishing an additional link to at least one additional network cell from a User Equipment (UE) (3) capable of using HSUPA and linked to a serving network cell (2.1a) via a first link. The proposed method comprises the steps of: upon detection of a soft/softer handover request from the user equipment (3), checking by a serving base station (2.1) of the plurality of base stations if at least a first predefined processing capacity is available at the additional network cell for allowing the requested handover;if said first processing capacity is available, controlling of said handover by means of the serving base station (2.1), elseif only a second predefined processing capacity lower than the first predefined processing capacity is available, sending an information message to the User Equipment (3) from the base station (2.1, 2.2) controlling the additional network cell upon reception of data from the User Equipment (3).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrative of a communication network in accordance with the present invention;

FIG. 2 is a first diagram illustrative of a protocol message flow between various entities of the communication network in accordance with the present invention;

FIG. 3 is a second diagram illustrative of a protocol message flow between various entities of the communication network in accordance with the present invention;

FIG. 4 is a schematic block diagram of a first system configuration of the communication network in accordance with the present invention; and

FIG. 5 is a schematic block diagram of a second system configuration of the communication network in accordance with the present invention.

Claims

1. A method of supporting soft/softer handover mechanisms for High-Speed Uplink Packet Access in a cellular communication network with a plurality of base stations, wherein said handover mechanisms include establishing an additional link to at least one additional network cell from a User Equipment capable of using HSUPA and linked to a serving network cell via a first link, the method comprising the steps of: upon detection of a soft/softer handover request from the User Equipment, checking by a serving base station of the plurality of base stations if at least a first predefined processing capacity is available at the additional network cell for allowing the requested handover;if said first processing capacity is available, controlling of said handover by means of the serving base station, elseif only a second predefined processing capacity lower than the first predefined processing capacity is available, sending an information message to the User Equipment from the base station controlling the additional network cell upon reception of data from the User Equipment.

2. The method of claim 1, further comprising the step of rejecting establishing said additional link by the base station controlling the additional network cell if the first and second processing capacities are not available.

3. The method of claim 1, further comprising the step of sending relative grant messages at least from the base station controlling the additional network cell to the User Equipment.

4. The method of claim 1, further comprising the step of checking a transport capacity between the serving base station and the base station controlling the additional network cell, if the serving base station and the base station controlling the additional network cell are distinct entities.

5. The method of claim 1, further comprising the step of soft combining data received from the User Equipment via different links with the User Equipment at the serving base station, if the first processing capacity is available.

6. The method of claim 1 further comprising the step of sending data received from the User Equipment via said additional link from the base station controlling the additional cell to the serving base station for selection combining with data received from the User Equipment via different links with the User Equipment at the serving base station, if the serving base station and the base station controlling the additional network cell are distinct entities.

7. A base station for use in a communication network supporting a HSUPA protocol, being adapted to, upon detection of a soft/softer handover request from a currently served User Equipment linked to a serving network cell which involves establishing an additional link from the User Equipment to at least one additional network cell: determine an available processing capacity in the additional network cell,control the handover if at least first predefined processing capacity is available in the additional network cell for allowing the requested handover.

8. The base station of claim 7, being further adapted to, following said request from a User Equipment currently being served by another base station, send an information message to the User Equipment upon reception of data from the User Equipment if the first processing capacity is not available.

9. The base station of claim 7, being further adapted to, following said request from a User Equipment currently being served by another base station, reject establishing said additional link if neither the first nor a second lower processing capacity is available.

10. The base station of claim 7, being further adapted to send Relative Grant messages to the User Equipment.

11. The base station of claim 7, being further adapted to check a transport capacity with respect to a data transmission to at least one other base station in the communication network.

12. The base station of claim 7, being further adapted to soft combine a data received from the User Equipment via different links with the User Equipment if the first processing capacity is available.

13. The base station of claim 7, being further adapted to send data received from the User Equipment via said additional link to another base station currently serving the User Equipment for selection combining with data received from the User Equipment at the other base station.

14. A communication network supporting a HSUPA protocol, comprising: at least one User Equipment capable of using of the HSUPA protocol and of requesting a soft/softer handover,at least one base station according to claim 7.

15. A computer program product, comprising program code sequences operable to set up a base station according to claim 7.