Resource allocation for direct terminal-to-terminal communication in a cellular system

1. A method comprising:

configuring common resources for supporting direct communication between terminals across a predefined registration area for direct communication comprising one or more cells of a cellular system of an evolved UNITS terrestrial radio access network, and

controlling an allocation of common resources for enabling direct communication between terminals across the predefined registration area,

said controlling comprising:

determining and assigning the allocation of common resources and the configuration thereof to a terminal being registered to the predefined registration area with a temporary identifier allocated by the cellular system identifying the terminal at least in cellular idle state to the cellular system, and

wherein said enabling comprises at least one of:

using the assigned resources for advertising the presence of the terminal for direct communication to terminals in the registration area, and

using the assigned resources for detecting the terminal as communication partner for direct communication by terminals in the registration area.

2. The method according to claim 1 , said configuring comprising at least one of:

negotiating the common resources with one or more base stations of cells comprised in the predefined registration area, and

renegotiating the common resources upon reconfiguration of the predefined registration area by activation or deactivation of one or more base stations of cells comprised in the predefined registration area.

3. The method according to claim 1 , said controlling comprising:

determining and assigning the allocation of common resources as a common direct access channel to a cell comprised in the predefined registration area or the predefined registration area.

4. The method according to claim 1 , said controlling comprising:

coordinating the allocation of common resources for enabling spatial reuse of common resources within the predefined registration area and/or between the predefined registration area and one or more overlapping and/or neighboring registration areas.

5. The method according to claim 1 , said controlling comprising:

updating and/or reconfiguring the allocation of common resources upon request by one or more terminals and/or system-based initiation.

6. The method according to claim 1 , the allocation of common resource comprising one or more of:

one or more reference signals, reference sequences, and/or beacons,

one or more physical channels for transmitting reference signals, reference sequences, and/or beacons,

transmit power for transmitting reference signals, reference sequences, and/or beacons, and

schedule for transmitting reference signals, reference sequences, and/or beacons.

7. The method according to claim 1 , the allocation of common resource being based on one or more of:

terminal profile characteristics and/or status of one or more terminals,

mobility contexts of one or more terminals and/or one or more cells,

characteristics and/or load level of common resources, and

availability of resources and/or interference status in the predefined registration area.

8. A computer program product comprising a non-transitory computer-readable storage medium bearing computer program code embodied therein for use with a computer, the computer program code comprising code for performing the method according to claim 1 .

9. The method according to claim 1 , wherein the method is operable at or by a dedicated registration server function for managing the predefined registration area which is operable as or at one or more base stations of cells comprised in the predefined registration area or a network.

10. The method according to claim 1 , wherein said enabling further comprises using the assigned resources for setting up a connection for direct communication between the terminal and a second terminal.

11. The method according to claim 1 , further comprising updating the registration of a terminal in cellular active state being registered to the registration area in a handover procedure.

12. An apparatus comprising:

at least one processor; and

at least one memory including computer program code, the at least one memory and the computer program code configured, with the at least one processor, to cause the apparatus to perform the following:

configure common resources for supporting direct communication between terminals across a predefined registration area for direct communication comprising one or more cells of a cellular system of an evolved UMTS terrestrial radio access network, and

control an allocation of common resources for enabling direct communication between terminals across the predefined registration area, said controlling comprising:

determining and assigning the allocation of common resources and the configuration thereof to a terminal being registered to the predefined registration area with a temporary identifier allocated by the cellular system identifying the terminal at least in cellular idle state to the cellular system, and

wherein said enabling comprises at least one of:

using the assigned resources for advertising the presence of the terminal for direct communication to terminals in the registration area, and

using the assigned resources for detecting the terminal as communication partner for direct communication by terminals in the registration area.

13. The apparatus according to claim 12 , wherein said at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus to perform at least one of the following:

negotiate the common resources with one or more base stations of cells comprised in the predefined registration area, and

renegotiate the common resources upon reconfiguration of the predefined registration area by activation or deactivation of one or more base stations of cells comprised in the predefined registration area.

14. The apparatus according to claim 12 , wherein said at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus to perform:

determine and assign the allocation of common resources as a common direct access channel to a cell comprised in the predefined registration area or the predefined registration area.

15. The apparatus according to claim 12 , wherein said at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus to perform:

coordinate the allocation of common resources for enabling spatial reuse of common resources within the predefined registration area and/or between the predefined registration area and one or more overlapping and/or neighboring registration areas.

16. The apparatus according to claim 12 , wherein said at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus to perform:

update and/or reconfigure the allocation of common resources upon request by one or more terminals and/or system-based initiation.

17. The apparatus according to claim 12 , wherein said at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus to perform:

control the allocation of common resource comprising one or more of:

one or more reference signals, reference sequences, and/or beacons,

one or more physical channels for transmitting reference signals, reference sequences, and/or beacons,

transmit power for transmitting reference signals, reference sequences, and/or beacons, and

schedule for transmitting reference signals, reference sequences, and/or beacons.

18. The apparatus according to claim 12 , wherein said at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus to perform:

control the allocation of common resource based on one or more of

terminal profile characteristics and/or status of one or more terminals,

mobility contexts of one or more terminals and/or one or more cells,

characteristics and/or load level of common resources, and

availability of resources and/or interference status in the predefined registration area.

19. The apparatus according to claim 12 , wherein the apparatus is operable as or at a dedicated registration server function for managing the predefined registration area which is operable as or at one or more base stations of cells comprised in the predefined registration area or a network element controlling one or more base stations of cells comprised in the predefined registration area.

20. The apparatus according to claim 12 , wherein said enabling further comprises using the assigned resources for setting up a connection for direct communication between the terminal and a second terminal.

21. The apparatus according to claim 12 , wherein said at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus to update the registration of a terminal in cellular active state being registered to the registration area in a handover procedure.

22. A method comprising:

registering a terminal for direct communication between terminals to a predefined registration area comprising one or more cells of a cellular system of an evolved UMTS terrestrial radio access network with a temporary identifier allocated by the cellular system identifying the terminal at least in cellular idle state to the cellular system,

receiving by the terminal an assignment indication of resources for enabling direct communication in the registration area,

wherein said enabling comprises at least one of:

using the assigned resources for advertising the presence of the terminal for direct communication to terminals in the registration area, and

using the assigned resources for detecting the terminal as communication partner for direct communication by terminals in the registration area.

23. The method according to claim 22 further comprising receiving a paging message for setup of a direct communication connection.

24. The method according to claim 22 further comprising one or more of:

requesting an assignment of resources for enabling direct communication in the registration area,

requesting an update of assigned resources for enabling direct communication in the registration, and

requesting reconfiguration of resources for enabling direct communication in the registration area.

25. A computer program product comprising a non-transitory computer-readable storage medium bearing computer program code embodied therein for use with a computer, the computer program code comprising code for performing the method according to claim 22 .

26. An apparatus comprising:

at least one processor; and

at least one memory including computer program code, the at least one memory and the computer program code configured, with the at least one processor, to cause the apparatus to perform the following:

register for direct communication between terminals to a predefined registration area comprising one or more cells of a cellular system of an evolved UNITS terrestrial radio access network with a temporary identifier allocated by the cellular system identifying the apparatus at least in cellular idle state to the cellular system,

receive an assignment indication of resources for enabling direct communication in the registration area,

wherein said enabling comprises at least one of:

using the assigned resources for advertising the presence of the apparatus for direct communication to terminals in the registration area, and

using the assigned resources for detecting the apparatus as communication partner for direct communication by terminals in the registration area.

27. The apparatus according to claim 26 wherein said at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus to receive a paging message for setup of a direct communication connection.

28. The apparatus according to claim 26 wherein said at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus to perform one or more of:

request an assignment of resources for enabling direct communication in the registration area,

request an update of assigned resources for enabling direct communication in the registration, and

request reconfiguration of resources for enabling direct communication in the registration area.