System and method for automatically configuring and integrating a radio base station into an existing wireless cellular communication network with full bi-directional roaming and handover capability

• US 20050148368A1
• Filed: 08/06/2004
• Published: 07/07/2005
• Est. Priority Date: 10/25/2002
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Intel Corporation
• Inventors: Lange, Peter, Scheinert, Stefan
• Granted Patent: US 7,477,920 B2
• Time in Patent Office: Days
• US Class Current: 455/561
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 36/00 Hand-off or reselection arrangements
• CPC Class Codes: H04W 60/00 Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: H04W 88/12 Access point controller devices

Abstract

A radio base station in a mobile communication network collects information about the network and exchanges data with a configuration device, the Internet System Manager (iSM). The iSM automatically configures and integrates the base station into the network by defining configuration parameter settings that allow fill interoperation of the base station with the network, with regards to roaming and handover in particular, without the need to add or modify parameter settings in other existing network elements. A very large number and high geographical density of such base stations is supported with full interoperation between them, allowing to overcome limitations of conventional mobile communication networks in this regard, by utilizing a certain combination of parameter settings and a new method to address the different base stations in the network.

Claims

1. A communications system comprising:

a radio base station for a wireless communication network, configured for connection to a central base station controller device, configured for collection of information about other surrounding base stations through its radio receiver and, based on the collected information and other carrier-specific requirements, configured to automatically integrate into the network with the aid of a central configuration device.

2. A system as claimed in claim 1 and further comprising:

a mobile switching center (MSC); and

a base station controller device handling communication between the base station and MSC, the base station controller device being co-located with the MSC and using the public Internet for communication with the base stations.

3. A system as claimed in claim 1 wherein the wireless network is selected from a group consisting of a GSM network, a COMA network and a 3G network.

4. A system as claimed in claim 1 wherein the base station utilizes a combination of network configuration parameter settings that allows full interoperation of the base station with the network for roaming and handover, without the need to modify parameter settings in other existing network elements.

5. A system as claimed in claim 4 wherein the combination of parameter settings makes the deployment of very large numbers of base stations in very high densities possible while maintaining full interoperation between them.

6. A system as claimed in claim 1 wherein the base station receiver operates in the downlink frequency band (base to mobile station) as well as the uplink frequency band (mobile to base station).

7. A system as claimed in claim 2 wherein the base station scans the downlink frequency band for BCCH (Broadcast Control Channel) signals from other base stations, measures the received signal strength, decodes broadcast parameters of these base stations such as the CGI (Cell Global Identifier, which contains the Location Area Code (LAC) and the Cell Identifier (CI)), the BSIC (Base Station Identity Code) and the neighbor cell list and reports the measurements to the configuration device.

8. A system as claimed in claim 7 and further comprising:

a configuration device that stores information about frequencies available to a carrier and automatically assigns a suitable radio frequency to the base station based on the measurements of the base station.

9. A system as claimed in claim 8 wherein the configuration device stores information about frequencies used as BCCH frequencies in the network and assigns to the base station the one among those frequencies where the lowest interference signal levels are received in the measurements.

10. A system as claimed in claim 9 wherein the configuration device identifies a strongest other base station that the base station can receive and assigns to that base station the same frequency that is also used as the BCCH frequency by the weakest received neighbor cell of the strongest other base station.

11. A system as claimed in claim 1 and further comprising:

a configuration device that stores information about frequencies available to a carrier and automatically assigns a suitable radio frequency to a base station, based on that information and on a random or cyclic algorithm.

12. A system as claimed in claim 7 wherein location area codes (LACs) and cell identifiers (CIs) are pre-defined for each MSC or for each BSC in the network, that are separate from LACs and CIs used by conventional base stations in the network, such that a plurality of base stations share a common cell global identifier (CGI) and therefore a common LAC and CI.

13. A system as claimed in claim 12 and further comprising:

a configuration device that has information stored about location area codes (LACs) used by different MSCs or BSCs of the network and, based on this information and on the measurements of the base station assigns a LAC to the base station out of the pre-defined set of LACs that belongs to the same MSC or BSC controlling the location area that the base station'"'"'s strongest neighbor cell belongs to, as well as linking that base station via the Internet to the base station controller connected to the same MSC.

14. A system as claimed in claim 2 and further comprising:

a configuration device that links the base station to the base station controller using a geographical database comprising zip code areas and/or individual streets in combination with location information provided by a user of the base station during activation.

15. A system as claimed in claim 13 wherein the configuration device uses a random or cyclic algorithm to ensure that the pre-defined LACs are evenly distributed among all base stations within an MSC area or BSC area.

16. A system as claimed in claim 7 and further comprising:

a configuration device that, based on the measurement reports, identifies other base stations that are adjacent to the base station and assigns the same LAC to it.

17. A system as claimed in claim 13 and further comprising:

a configuration device that, based on the measurement reports, identifies other base stations are adjacent to the base station and assigns a different LAC to it out of the pre-defined set of LACs.

18. A system as claimed in claim 1 wherein frequencies to be used by the base station are pre-defined that are different from the frequencies used by other base stations in the network and added to neighbor lists of those other base stations in the network and to their neighbor cell descriptions in their BSCs.

19. A system as claimed in claim 1 wherein all BCCH frequencies used in the network are pre-defined as possible frequencies to be used by the base station and added to neighbor lists of those other base stations in the network and to their neighbor cell descriptions in their BSCs.

20. A system as claimed in claim 7 and further comprising:

a configuration device that, based on the signal level measurement reports of the base station, identifies other base stations are adjacent to the base station, adds the BCCH frequencies of the adjacent base stations to the neighbor list of the base station and adds cell descriptions of the adjacent base stations to the base station'"'"'s neighbor list in the base station controller, wherein the cell descriptions contain the adjacent base stations'"'"' radio frequency (ARFCN), CGI (cell global identifier) and BSIC (base station identity code).

21. A system as claimed in claim 1 wherein a certain number of neighbor cell descriptions are reserved in a conventional base station controller for descriptions of the base stations as neighbors to the conventional base station, and filed with pre-defined parameters such as the radio frequencies (ARFCN), the cell global identifiers (CGI) and the base station identity codes (BSIC) that the base stations will use.

22. A system as claimed in claim 1 wherein a certain number of base station identity codes (BSIC) are assigned for use by the base stations and written into pre-defined neighbor lists for all conventional base stations in the network that are stored in a conventional base station controller.

23. A system as claimed in claim 7 and further comprising:

a configuration device that stores information about base station identity codes (BSIC) used in the network and, based on this information and on the measurement reports from the base station, assigns a BSIC to the base station that differs from the strongest other base station in the area using the same radio frequency.

24. A system as claimed in claim 7 and further comprising:

a configuration device that, based on the measurement reports from the base stations, creates for every base station in the network a pointer list of base stations that are adjacent to that base station and transfers that list to the base station controller that is connected to the same MSC that that base station is connected to.

25. A system as claimed in claim 24 wherein the base station controller uses the pointer list to direct handovers from one base station to another base station that is on that base station'"'"'s pointer list.

26. A system as claimed in claim 2 wherein the base station controller keeps a record for every base station of which mobiles have last performed a location update procedure with that base station and polls those mobiles in regular intervals to establish whether they are still in that base station'"'"'s coverage area, or alternatively deletes a mobile'"'"'s record after it has been inactive for a specified period of time.

27. A system as claimed in claim 26 wherein the base station controller uses the mobile'"'"'s records to direct mobile terminating calls (MTC) to one particular base station only.

28. A system as claimed in claim 27 wherein the base station controller, when receiving a handover request message from the MSC it is connected to, sends a channel activation command to all base stations that share a CGI specified as the handover target in the handover request message and that are on the pointer list of the base station where the handover request was initiated, that base station being identified by its CGI in the handover request message.

29. A system as claimed in claim 28 wherein the base station controller, when receiving a handover detection message from a base station in response to a channel activation command, signals to all other base stations that the same channel activation command was sent to release the activated channel again.

30. A system as claimed in claim 13 wherein the base station controller, when addressing the base station that is sharing a common CGI with other such base stations, uses an IP address to address that base station/

31. A system as claimed in claim 13 wherein the configuration device, when addressing the base station, shares a common CGI with other such base stations and uses an IP address to address that base station.

32. A system as claimed in claim 30 wherein a call taken over in the handover is immediately transferred from its original channel to another channel in order to clear the original channel for further handover requests.

33. A system as claimed in claim 2, wherein the base station controller allows greater than 64 neighbor relations per cell.

34. A system as claimed in claim 1 wherein transmit power level is adjusted, between a minimum and maximum value, according to user input about radio coverage objectives.

35. A system as claimed in claim 7 wherein transmit power level is adjusted, between a minimum and maximum value, based on a number of neighbor cells that the base station was able to receive in its measurements.

36. A system as claimed in claim 1 wherein transmit power level is adjusted, between a minimum and maximum value, based on average signal levels and bit error rates reported by mobile stations served.

37. A system as claimed in claim 1 wherein the base station continuously monitors signal levels and bit error rates reported from mobile stations served and reselects a new suitable frequency when poor radio conditions persist over a certain period of time.

38. A system as claimed in claim 1, wherein the base station has an integrated GPS receiver for determining its location.

39. A system as claimed in claim 1, wherein the base station has an integrated Bluetooth or WiFi transceiver to communicate locally with mobile stations and exchange location information.

40. A method of numbering location area codes (LACs) in a wireless communication network so that at least one digit of the LACs identifies a mobile switching center (MSC) controlling a location area and at least one other digit of the LACs identifies a base station controller (BSC) controlling the location area.