Method and apparatus for transmitting a synchronization beacon in a wireless communication network
First Claim
1. A method of transmitting a synchronization signal from a wireless fixed base station (WFB) to a wireless terminal (WT) configured for selective communication with the WFB in a wireless communication network, the synchronization signal being communicated by the WFB as part of a time-division signal having a plurality of timeslots, said method comprising the steps of:
- (a) transmitting a pair of synchronization beacons from the WFB for receipt by the WT, each synchronization beacon in said pair occupying a separate timeslot position in the time-division signal communicated by the WFB, so that the timeslot occupied by one synchronization beacon in said pair is temporally spaced from a timeslot occupied by another synchronization beacon in said pair;
(b) broadcasting the timeslot position for each of said two synchronization beacons by the WFB for receipt by the WT as a beacon position message;
(c) in the WT, receiving and decoding said beacon position message;
(d) synchronizing the WT to the WFB using one of said two synchronization beacons; and
(e) if transmission of said one of said two synchronization beacons is discontinued by the WFB, synchronizing the WT to the WFB using the other one of said two synchronization beacons.
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Accused Products
Abstract
The present invention provides a method and apparatus for transmitting a synchronization beacon from a wireless base station to a wireless terminal in a wireless communication network installed in a building. The wireless network comprises a private branch exchange (PBX) connected to a wireless fixed base station (WFB) having a plurality of cell antennae units (CAUs) connected thereto. In a first embodiment, the plurality of CAUs are located in a single cell of the wireless network and are configured to receive two synchronization beacons from the WFB. In a second embodiment, each CAU is located in a separate cell in the network and is configured to receive a single synchronization beacon from the WFB. The synchronization beacon(s) is/are managed by the WFB and WT to virtually eliminate loss of synchronization between the WFB and WT if the frequency-timeslot at which the beacon is transmitted is changed or if transmission of the beacon is temporarily discontinued. In addition, synchronization between the WFB and WT is also maintained when the WT is moved to another cell in the wireless network.
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Citations
38 Claims
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1. A method of transmitting a synchronization signal from a wireless fixed base station (WFB) to a wireless terminal (WT) configured for selective communication with the WFB in a wireless communication network, the synchronization signal being communicated by the WFB as part of a time-division signal having a plurality of timeslots, said method comprising the steps of:
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(a) transmitting a pair of synchronization beacons from the WFB for receipt by the WT, each synchronization beacon in said pair occupying a separate timeslot position in the time-division signal communicated by the WFB, so that the timeslot occupied by one synchronization beacon in said pair is temporally spaced from a timeslot occupied by another synchronization beacon in said pair;
(b) broadcasting the timeslot position for each of said two synchronization beacons by the WFB for receipt by the WT as a beacon position message;
(c) in the WT, receiving and decoding said beacon position message;
(d) synchronizing the WT to the WFB using one of said two synchronization beacons; and
(e) if transmission of said one of said two synchronization beacons is discontinued by the WFB, synchronizing the WT to the WFB using the other one of said two synchronization beacons. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
(g) discontinuing transmission of one of said dummy bearer beacons for a first predetermined time period;
(h) resuming transmission of said one of said dummy bearer beacons upon expiration of said first predetermined time period; and
(i) repeating said steps (g) through (h) upon expiration of a second predetermined time period.
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4. The method of claim 3, wherein said first predetermined time period is approximately 0.16 seconds.
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5. The method of claim 3, wherein said second predetermined time period is approximately 29.44 seconds.
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6. The method of claim 3, further comprising the steps of:
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(j) discontinuing transmission of the other one of said dummy bearer beacons for a third predetermined time period at a predetermined delay from said discontinuance of said one of said dummy bearer signal beacons;
(k) resuming transmission of said other one of said dummy bearer signal beacons upon expiration of said third predetermined time period; and
(l) repeating said steps (j) through (k) upon expiration of a fourth predetermined time period.
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7. The method of claim 6, wherein said third predetermined time period is approximately 0.16 seconds.
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8. The method of claim 6, wherein said fourth predetermined time period is approximately 29.44 seconds.
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9. The method of claim 6, wherein said predetermined delay is approximately 3.84 seconds.
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10. The method of claim 3, further comprising the step of changing the timeslot position of each of said dummy bearer signal beacons at a predetermined time interval.
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11. The method of claim 10, wherein said predetermined time interval is approximately equal to 160 seconds.
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12. The method of claim 1, wherein at least one of said synchronization beacons is a traffic bearer signal beacon communicated between the WFB and the WT during a communication session, said method further comprising the step of converting the traffic bearer synchronization beacon to a dummy bearer synchronization beacon upon termination of said communication session between the WFB and the WT.
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13. The method of claim 1, wherein said beacon position message is broadcast from the WFB to the WT as a short page MAC (media-access control) layer broadcast message.
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14. The method of claim 1, wherein the time-division signal communicated by the WFB to the WT is a TDMA (Time-Division Multiple Access) signal.
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15. The method of claim 1, wherein the wireless communication network comprises a cell having a cell antennae unit (CAU) located therein and connected to the wireless fixed base.
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16. The method of claim 1, wherein said separate timeslot positions are separated from each other by two timeslot positions.
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17. The method of claim 1, further comprising transmitting upper data link layer information from the WFB using one of said two sychronization beacons.
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18. The method of claim 1, wherein said step (b) comprises continuously broadcasting the timeslot position of each of said two synchronization beacons by the WFB for receipt by the WT as a beacon position message.
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19. A method of transmitting a synchronization signal from a wireless fixed base station (WFB) to a wireless terminal (WT) configured for selective communication with the WFB in a wireless communication network, the synchronization signal being communicated by the WFB as part of a time-division signal having a plurality of timeslots, said method comprising the steps of:
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(a) transmitting a synchronization beacon for a predetermined time period at a predetermined timeslot position in the time-division signal communicated by the WFB for receipt by the WT, said synchronization beacon being in a living state during said predetermined time period;
(b) broadcasting said timeslot position of said synchronization beacon by the WFB for receipt by the WT as a beacon position message;
(c) in the WT, receiving and decoding said beacon position message;
(d) synchronizing the WT to the WFB using said synchronization beacon; and
(e) upon expiration of said predetermined time period of said step (a), changing the timeslot of said synchronization beacon. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
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31. A system for transmitting a synchronization signal in a cell of a wireless communication network, the synchronization signal being a part of a time-division signal, said system comprising:
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a private branch exchange (PBX); and
a wireless fixed base station (WFB) connected to said PBX and configured for transmitting two synchronization beacons at separate timeslot positions in the time-division signal for receipt by said WT, the two synchronization beacons being separated from each other;
said WFB broadcasting the timeslot positions of the two synchronization beacons for receipt by said WT as a beacon position message, said WFB transmitting upper data link layer information for receipt by said WT as a short page message; and
said WT receiving and decoding said beacon position message broadcast by said WFB, said WT synchronizing to said WFB using a first one of the two synchronization beacons, said WT synchronizing to said WFB using the other one of the two synchronization beacons if transmission of the first one of the two synchronization beacons by said WFB is discontinued. - View Dependent Claims (32, 33)
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34. A system for transmitting a synchronization signal in a cell of a wireless communication network including a wireless terminal (WT) and a private branch exchange (PBX), the synchronization signal being a part of a time-division signal, said system comprising:
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a wireless fixed base station (WFB) connected to the PBX and configured for transmitting two synchronization beacons at separate timeslot positions in the time-division signal for receipt by the WT, so that the timeslot occupied by one synchronization beacon is temporally spaced from a timeslot occupied by another synchronization beacon;
said WFB broadcasting the timeslot positions of the two synchronization beacons for receipt by the WT as a beacon position message, said WFB transmitting upper data link layer information for receipt by the WT as a short page message; and
the WT receiving and decoding said beacon position message broadcast by said WFB, the WT synchronizing to said WFB using a first one of the two synchronization beacons and synchronizing to said WFB using the other one of the two synchronization beacons if transmission of the first one of the two synchronization beacons by said WFB is discontinued.
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35. A system for transmitting a synchronization signal in a plurality of cells in a wireless communication network including a private branch exchange (PBX), the synchronization signal being a part of a time-division signal, said system comprising:
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a wireless terminal (WT); and
a wireless fixed base station (WFB) connected to the PBX and configured for transmitting a synchronization beacon for a predetermined time period at a first predetermined timeslot position in the time-division signal for receipt by said WT, the synchronization beacon being in a living state during said predetermined time period and in an expired state upon expiration of said predetermined time period;
said WFB broadcasting said first timeslot position of the synchronization beacon for receipt by said WT as a beacon position message, said WFB transmitting upper data link layer information for receipt by said WT as a short page message;
said WT receiving and decoding said beacon position message broadcast by said WFB, said WT synchronizing to said WEB using said synchronization beacon in the living state;
said WFB transmitting a new synchronization beacon at a second predetermined timeslot position as soon as the synchronization beacon enters the expired state, said second predetermined timeslot position of said new synchronization beacon being different from said timeslot position of said synchronization beacon in the expired state;
said synchronization beacon in the expired state including said second predetermined timeslot position of said new synchronization beacon. - View Dependent Claims (36, 37)
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38. In a system for transmitting a synchronization signal in a plurality of cells in a wireless communication network including a wireless terminal (WT) and a private branch exchange (PBX), the synchronization signal being a part of a time-division signal,
a wireless fixed base station (WFB) connected to the PBX and configured for transmitting a synchronization beacon for a predetermined time period at a first predetermined timeslot position in the time-division signal for receipt by the WT, the synchronization beacon being in a living state during said predetermined time period and in an expired state upon expiration of said predetermined time period; -
said WFB broadcasting said first timeslot position of the synchronization beacon for receipt by the WT as a beacon position message, and said WFB transmitting upper data link layer information for receipt by the WT as a short page message;
the WT receiving and decoding said beacon position message broadcast by said WFB, and the WT synchronizing to said WFB using said synchronization beacon in the living state;
said WFB transmitting a new synchronization beacon at a second predetermined timeslot position as soon as the synchronization beacon enters the expired state, said second predetermined timeslot position of said new synchronization beacon being different from said timeslot position of said synchronization beacon in the expired state;
said synchronization beacon in the expired state including said second predetermined timeslot position of said new synchronization beacon.
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Specification