METHOD AND APPARATUS FOR ASSIGNING A LOGICAL ADDRESS IN A COMMUNICATION SYSTEM

• US 20140317314A1
• Filed: 11/09/2012
• Published: 10/23/2014
• Est. Priority Date: 11/09/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Nigam, Anshuman, Agiwal, Anil, Chang, Young-Bin
• Granted Patent: US 10,003,566 B2
• Time in Patent Office: Days
• US Class Current: 709/245
• CPC Class Codes: H04L 61/50 Address allocation
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A method and a system for assigning a unique logical address to a mobile station in a cloud cell are provided. The method includes selecting, by the master base station, a unique logical address from an associated set of addresses, wherein the set of addresses is a subset of a common address space, and assigning the unique logical address to the mobile station so that the mobile station and each of the plurality of base stations communicate in the cloud cell using the assigned unique logical address.

Claims

1. A method for assigning a logical address to a mobile station in a cloud cell, wherein the cloud cell comprises a plurality of base stations, each of the plurality of base stations comprising a master base station and one or more slave base stations, the method comprising:

selecting, by the master base station, an unique logical address from an associated set of addresses, wherein the set of addresses is a subset of a common address space; and

assigning the unique logical address to the mobile station so that the mobile station and each of the plurality of base stations communicate in the cloud cell using the assigned unique logical address.

2. The method of claim 1, wherein each of the plurality of base stations in a geographical area is assigned a disjoint set of addresses from the common address space.

3. The method of claim 1, further comprising:

notifying assignment of the unique logical address to the slave base stations in the cloud cell.

4. The method of claim 1, further comprising:

transmitting the unique logical address currently assigned to the mobile station to a new base station currently being added to the cloud cell.

5. The method of claim 4, further comprising:

determining whether the unique logical address currently assigned to the mobile station belongs to a set of addresses associated with the new base station;

determining whether the unique logical address is assigned to another mobile station belonging to another cloud cell if the unique logical address belongs to the set of addresses associated with the new base station; and

transmitting a notification to the master base station indicating that the unique logical address does not belong to the set of addresses associated with the new base station.

6. The method of claim 5, further comprising:

transmitting a notification to the master base station indicating that the unique logical address belongs to the set of addresses associated with the new base station and the unique logical address is not assigned to another mobile station.

7. The method of claim 6, further comprising:

determining whether any base station exists in the cloud cell with the set of addresses identical to the set of addresses of the new base station upon receiving the notification;

removing the determined base station having the set of addresses identical to the set of addresses of the new base station; and

adding the new base station to the cloud cell as a slave base station.

8. The method of claim 6, further comprising:

determining whether there exists any base station in the cloud cell having the set of addresses identical to the set of addresses of the new base station upon receiving the notification; and

rejecting inclusion of the new base station in to the cloud cell if any base station in the cloud cell is having the set of addresses identical to the set of addresses of the new base station.

9. The method of claim 5, further comprising:

selecting a unique logical address from the set of addresses associated with the new base station; and

transmitting a notification indicating that the unique logical address belongs to the set of addresses associated with the new base station and the unique logical address is assigned to the another mobile station to the master base station, wherein the notification includes the unique logical address selected from the set of addresses associated with the new base station.

10. The method of claim 9, further comprising:

determining whether any base station exists in the cloud cell having the set of addresses identical to the set of addresses of the new base station upon receiving the notification;

removing the determined base station having the set of addresses identical to the set of addresses of the new base station; and

adding the new base station to the cloud cell as a slave base station.

11. The method of claim 10, further comprising:

re-assigning the unique logical address received in the notification to the mobile station; and

notifying assignment of the unique logical address to the slave base stations in the cloud cell.

12. The method of claim 9, further comprising:

determining whether any base station exists in the cloud cell having the set of addresses identical to the set of addresses of the new base station upon receiving the notification; and

rejecting inclusion of the new base station to the cloud cell if any base station in the cloud cell is having the set of addresses identical to the set of addresses of the new base station.

13. The method of claim 11, wherein the transmitting of the unique logical address currently assigned to the mobile station to the new base station comprises:

transmitting, to the new base station, the unique logical address currently assigned to the mobile station and at least one of a first indicator indicating whether one or more base stations in the cloud cell are having same set of addresses from which the unique logical address is currently assigned to the mobile station and a second indicator indicating whether all the base stations in the cloud cell are having the same set of addresses from which the unique logical address is currently assigned to the mobile station.

14. The method of claim 13, wherein the selecting of the unique logical address from the set of addresses associated with the new base station comprises:

determining whether one or more of the base stations in the cloud cell has the set of addresses identical to the set of addresses associated with the new base station based on the least one of the first indicator and the second indicator if the unique logical address is assigned to another mobile station;

selecting a unique logical address from the set of addresses associated with the new base station if none of the base stations in the cloud cell has identical set of addresses as the new base station; and

identifying one or more unassigned logical addresses selected from the set of addresses associated with the new base station if all the base stations in the cloud cell has identical set of addresses as the new base station.

15. The method of claim 14, wherein the transmitting of the notification indicating that the unique logical address belongs to the set of addresses and the unique logical address is assigned to the another mobile station comprises:

transmitting a notification including the unique logical address selected from the set of addresses associated with the new base station.

16. The method of claim 15, wherein the transmitting of the notification indicating that the unique logical address belongs to the set of addresses and the unique logical address is assigned to the another mobile station comprises:

transmitting a notification including a list of the unassigned logical addresses identified from the set of addresses of the new base station.

17. The method of claim 14, wherein the transmitting of the notification indicating that the unique logical address belongs to the set of addresses and the unique logical address is assigned to the another mobile station comprises:

transmitting a notification to the master base station indicating that the unique logical address belongs to the set of addresses associated with the new base station and the unique logical address is assigned to another mobile station if the one or more of the base stations in the cloud cell has identical logical addresses as the new base station.

18. The method of claim 15, wherein the re-assigning of the unique logical address to the mobile station comprises:

re-assigning the unique logical address received in the notification to the mobile station.

19. The method of claim 16, wherein the re-assigning of the unique logical address to the mobile station comprises:

determining one or more unassigned logical addresses in the set of addresses associated with each of the base stations in the cloud cell upon receiving the notification;

determining an identical unique logical address from the determined one or more unassigned logical addresses and the list of unassigned logical addresses received from the new base station; and

assigning the determined identical unique logical address to the mobile station.

20. The method of claim 17, wherein the re-assigning of the unique logical address to the mobile station comprises:

identifying a set of addresses which is associated with the least number of base stations in the cloud cell;

obtaining a unique logical address from the identified set of addresses; and

assigning the unique logical address to the mobile station.

21. A base station for assigning a logical address to a mobile station in a cloud cell, the base station comprising:

a communication interface configured to communicate with other base stations;

a transceiver configured to communicate with the mobile station; and

a controller configured to select a unique logical address from an associated set of addresses, wherein the set of addresses is a subset of a common address space, and to assign the unique logical address to the mobile station so that the mobile station and each of a plurality of base stations communicate in the cloud cell using the assigned unique logical address.

22. A method for allocating disjoint sets of addresses to a plurality of base stations in a geographical area, the method comprising:

determining a number of base stations located adjacent to each other in a geographical area;

determining an identifier associated with each of the base stations in the geographical area;

deriving disjoint sets of addresses from a common address space based on the identifier of each base station and the number of base stations; and

allocating the disjoint set of addresses to each of the base stations so that each of the base stations uniquely assigns a single unicast logical address to a mobile station in a respective cloud cell using the associated disjoint set of addresses.

23. The method of claim 22, wherein the deriving of the disjoint sets of addresses from the common address space based on the identifier of each base station and the number of base stations comprises:

deriving the disjoint sets of addresses from the common address space such that each of the disjoint sets of addresses contains logical addresses which satisfy the equality “

Address”

modulo “

number of base stations”

==“

Base Station Identifier”

modulo “

number of base stations”

.

24. The method of claim 22, wherein the deriving of the disjoint sets of addresses from the common address space based on the identifier of each base station and the number of base stations comprises:

deriving the disjoint sets of addresses from the common address space such that each of the disjoint sets of addresses contains 2^(k-n) logical addresses, where ‘

k’

is size of the common address space and ‘

n’

is an integer.

25. The method of claim 24, wherein the number of base stations is equal to value 2ⁿ.

26. The method of claim 22, wherein each of the disjoint sets of addresses is a subset of the common address space.

27. A network entity for allocating disjoint sets of addresses to a plurality of base stations in a geographical area, the network entity comprising:

a communication interface configured to communicate with a base station;

a controller configured to determine a number of base stations located adjacent to each other in a geographical area, to determine an identifier associated with each of the base stations in the geographical area, to derive disjoint sets of addresses from a common address space based on the identifier of each base station and the number of base stations, and to allocate the disjoint set of addresses to each of the base stations so that each of the base stations uniquely assigns a single unicast logical address to a mobile station in a respective cloud cell using the associated disjoint set of addresses.