التفاصيل البيبلوغرافية
| العنوان: |
Smooth Handover in a Wireless Local Area Network |
| Document Number: |
20080273495 |
| تاريخ النشر: |
November 6, 2008 |
| Appl. No: |
11/597845 |
| Application Filed: |
May 26, 2005 |
| مستخلص: |
A process for operation of a data link transmitting data packets between a base station and one or more mobile stations within transmission phases. A start signal indicates the start of each transmission phase that is managed by the base station. For preparation of a handover procedure the mobile station switches into a monitoring phase, wherein the radio traffic is listened to and another base station suitable for the data packet transmission is sought. The mobile station performs data packet transmission in every mth transmission phase, “m” designating a natural number greater than “1”, and after data packet transmission has been effected, the mobile station is omitted from the data packet transmission for at least one subsequent transmission phase. |
| Inventors: |
Becker, Thomas (Berlin, DE); Krause, Frank-Michael (Berlin, DE); Methfessel, Michael (Frankfurt (Oder), DE); Tittelbach-Helmrich, Klaus (Frankfurt (Oder), DE); Lunn, Andrew Stuart (Othmarsingen, CH) |
| Claim: |
1-21. (canceled) |
| Claim: |
22. A method for operating a data link between a base station and one or more mobile stations, the method comprising: indicating start of a transmission phase through emission of a beacon signal; responsive to the beacon signal, configuring a transmission interface as a wireless interface between the base station and a mobile station for the transmission phase, and managing the transmission interface by the base station; during the transmission phase, transmitting data packets between the base station and the mobile station; preparing for a handover procedure by switching the mobile station into a monitoring phase, wherein the mobile station listens to radio traffic and seeks an alternative base station suitable for data packet transmission during the monitoring phase; transmitting the data packets in every mth transmission phase of the mobile station, where m is a natural number greater than one; and after the data packet transmission has been effected, omitting the mobile station from the data packet transmission for at least one subsequent transmission phase. |
| Claim: |
23. The method of claim 22, wherein the data packet transmission between the base station and the one or more mobile stations occurs during transmission phases, and wherein the monitoring phase lies outside the transmission phases. |
| Claim: |
24. The method of claim 22, wherein the monitoring phase of the mobile station at least partly overlaps at least one omitted transmission phase, the mobile station being omitted from the data packet transmission with the base station during the at least one omitted transmission phase. |
| Claim: |
25. The method of claim 22, wherein the base station and the alternative base station operate with different transmission frequencies and beacon signals of the base station and the alternative base station are mutually asynchronous. |
| Claim: |
26. The method of claim 22, wherein beacon signals of the base station and the alternative base station are made equidistant. |
| Claim: |
27. The method of claim 22, wherein each mobile station effects a data packet transmission in every other transmission phase of the mobile station. |
| Claim: |
28. The method of claim 22, wherein if an alternative base station suitable for the data packet transmission is found during the preparing for the handover procedure, the mobile station sets up a parallel link with the alternative base station, the parallel link including a link between the mobile station and the base station and a link between the mobile station and the alternative base station, the parallel link being set up during time windows lying outside the transmission phases used for the data packet transfer between the mobile station and the base station. |
| Claim: |
29. The method of claim 28, wherein the time windows used for the parallel link include omitted transmission phases, the omitted transmission phases being transmission phases wherein the mobile station is omitted from the data packet transmission with the base station. |
| Claim: |
30. The method of claim 28, wherein the parallel link is an interim parallel link, and wherein after the link with the alternative base station has been set up, the parallel link with the base station is ended. |
| Claim: |
31. The method of claim 22, wherein the one or more mobile stations are assigned to even transmission phases used for the data packet transmission with the base station. |
| Claim: |
32. The method of claim 22, wherein the data packet transmission takes place under a WLAN standard and the base station is a WLAN access point. |
| Claim: |
33. The method of claim 22, wherein through the emission of the beacon signal a contention-free period is created for reserving the interface for a predetermined frequency range. |
| Claim: |
34. The method of claim 22, wherein an end of each transmission phase is indicated by emission of a contention-free end signal by the base station. |
| Claim: |
35. The method of claim 33, wherein between the transmission phases the interface in the predetermined frequency range is released for contention periods. |
| Claim: |
36. The method of claim 22, wherein a time interval between two consecutive beacon signals is at least twice as large as contention-free periods between the two consecutive beacon signals. |
| Claim: |
37. The method of claim 22, wherein duration of the monitoring phase of the mobile station is at least 1.5 times a time interval between two consecutive beacon signals. |
| Claim: |
38. The method of claim 22, wherein the data packets include real-time critical data streams and are transmitted during the data packet transmission. |
| Claim: |
39. The method of claim 22, wherein a time interval between two beacon signals is between 5 ms and 15 ms. |
| Claim: |
40. A base station for operating a data link with one or more mobile stations, comprising: a control device configured to exchange data packets with the mobile stations within transmission phases; means for assigning the transmission phases to the one or more mobile stations in such a manner that each mobile station performs data packet transmission in every mth transmission phase, where m is a natural number greater than one, and means for excluding each mobile station from the data packet transmission, after the data packet transmission has been effected, for at least one following transmission phase. |
| Claim: |
41. A mobile station for operating a data link with a base station, the mobile station comprising a mobile station control device, the mobile station control device further comprising: means for exchanging data packets with the base station within transmission phases, means for switching into a monitoring phase outside the transmission phases, the monitoring phase for listening to radio traffic and for seeking another base station suitable for data packet transmission, means for performing the data packet transmission in every mth transmission phase, where m is a natural number greater than one, and means for omitting the data packet transmission during at least one transmission phase subsequent to the transmission phase including the data packet transmission. |
| Current U.S. Class: |
370/331 |
| Current International Class: |
04; 04 |
| رقم الانضمام: |
edspap.20080273495 |
| قاعدة البيانات: |
USPTO Patent Applications |
