Wireless base station to base station synchronization in a communication system, such as a system employing a short range frequency hopping or time division duplex scheme
First Claim
1. A system for wirelessly exchanging communications with at least one mobile unit, the system comprising:
- more than two base station units coupled to a network, wherein each base station unit includes an internal clock, and a processor and at least one radio configured to communicate wirelessly with the mobile unit under a Bluetooth protocol, wherein the Bluetooth protocol is a short-range, frequency hopping protocol for transmitting and receiving information during time division duplex pairs of transmit and receive slots;
wherein each base station unit is further configured to;
(a) enter into a synchronization mode, (b) receive a sync signal from a neighboring base station unit, (c) determine if the neighboring base station unit is synchronized based on the received sync signal, (d) if the neighboring base station unit is synchronized, then synchronize the internal clock based on the received sync signal, wherein the synchronizing is performed without assistance from a system controller, (e) select one transmit slot from the pairs of slots, (f) lock the other base station units from transmitting on the one selected transmit slot, (g) wirelessly transmit synchronization information during the one selected transmit slot, (h) permit the other base station units to unlock, and (i) exit the synchronization mode.
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Accused Products
Abstract
In a network, a method is disclosed for wirelessly exchanging communications with at least one mobile unit. The network includes first and second base stations units coupled to the network, and may include a system controller. The method includes: receiving a communication signal from the second base station unit, wherein the first and second base station units are configured to employ a wireless communications protocol, and wherein the wireless communications protocol does not provide for handoff of communications links between base station units; at the first base station unit, determining if the second base station unit has been synchronized based on the communication signal; at the first base station unit, if the second base station unit is synchronized, then synchronizing an internal clock based on the synchronized second base station, wherein the synchronizing is performed without assistance from a system controller.
175 Citations
62 Claims
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1. A system for wirelessly exchanging communications with at least one mobile unit, the system comprising:
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more than two base station units coupled to a network, wherein each base station unit includes an internal clock, and a processor and at least one radio configured to communicate wirelessly with the mobile unit under a Bluetooth protocol, wherein the Bluetooth protocol is a short-range, frequency hopping protocol for transmitting and receiving information during time division duplex pairs of transmit and receive slots;
wherein each base station unit is further configured to;
(a) enter into a synchronization mode, (b) receive a sync signal from a neighboring base station unit, (c) determine if the neighboring base station unit is synchronized based on the received sync signal, (d) if the neighboring base station unit is synchronized, then synchronize the internal clock based on the received sync signal, wherein the synchronizing is performed without assistance from a system controller, (e) select one transmit slot from the pairs of slots, (f) lock the other base station units from transmitting on the one selected transmit slot, (g) wirelessly transmit synchronization information during the one selected transmit slot, (h) permit the other base station units to unlock, and (i) exit the synchronization mode. - View Dependent Claims (2, 3)
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4. In a network for wirelessly exchanging communications with mobile units, wherein the network includes first and second base stations units coupled to the network, and may include a system controller coupled to the network, a method comprising:
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at the first base station unit, receiving a communications signal from the second base station unit, wherein the first and second base station units are configured to employ a wireless communications protocol, and wherein the wireless communications protocol does not provide for handoff of communications links between base station units;
at the first base station unit, determining if the second base station unit has been synchronized based on the communications signal; and
at the first base station unit, if the second base station unit is synchronized, then synchronizing an internal clock based on the synchronized second base station, wherein the synchronizing is performed without assistance from a system controller or mobile units. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 36, 37, 39, 40)
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24. In a network for wirelessly exchanging communications with at least one mobile unit, wherein the network includes multiple network access points coupled to the network, a method performed by at least some network access points comprising:
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receiving a sync signal from a neighboring network access point;
locking at least neighboring network access points from synchronizing;
choosing a transmission slot under a slotted communications protocol;
recording synchronization information, and unlocking the neighboring network access points.
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35. A computer-readable medium containing a data structure for use by a network access point in a communications network, the data structure comprising:
at least one record stored at the network access point in the communications network, wherein each record comprises;
a unique identifier for the network access point, wherein the network access point may communicate wirelessly under a short-range wireless communications protocol with a neighboring network access point, wherein the short-range wireless protocol permits the neighboring network access point to communicate wirelessly with an effective range of less than 500 meters;
a synchronization wave number identifying when the network access point is synchronized; and
a synchronization transmit slot identifying when the network access point transmits its synchronization information to neighboring network access points.
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38. A computer-readable medium containing a data structure for use by a local base station unit in a communications network, the data structure comprising:
at least one record stored at the local base station unit in the communications network, wherein each record comprises;
a unique identifier for a neighboring base station unit, wherein the local base station unit may communicate wirelessly with the neighboring base station unit under a short-range wireless communications protocol, wherein the short-range wireless protocol permits wireless communication with an effective range of less than 500 meters;
a synchronization wave number identifying when the neighboring base station unit is synchronized; and
a synchronization transmit slot identifying when the neighboring base station unit transmits its synchronization information.
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41. A computer-readable medium whose contents cause a local short-range wireless communications switch to perform synchronization with a neighboring short-range wireless communications switch in a communications network, the method comprising:
receiving a communications signal from the neighboring short-range wireless communications switch, wherein the local and neighboring short-range wireless communications switches are configured to employ a wireless communications protocol, and wherein the wireless communications protocol permits wireless communication with an effective range of less than 500 meters;
determining if the neighboring short-range wireless communications switch has been synchronized based on the communications signal; and
if the neighboring short-range wireless communications switch is synchronized, then synchronizing an internal clock of the local short-range wireless communications switch based on the synchronized neighboring short-range wireless communications switch, wherein the synchronizing is performed without assistance from a system controller or mobile units. - View Dependent Claims (42, 43, 44, 45, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 59, 60)
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46. In a picocellular communications network, wherein at least one mobile unit communicates with at least a portion of the network, an apparatus comprising:
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a wireless network access point coupled to the picocellular communications network, wherein the network access point includes;
a memory, at least one radio for transmitting and receiving data on respective transmit and receive slots, and a processor coupled to the memory and the radio, wherein the network access point is configured for;
receiving a communications signal from a nearby network access point, wherein the radio and processor are configured to employ a slotted wireless communications protocol, and wherein the wireless communications protocol does not provide for handoff of communications links between network access points;
determining if the nearby network access point has been synchronized based on the communications signal; and
if the nearby network access point is synchronized, then synchronizing the transmit and receive slots based on the synchronized nearby network access point, wherein the synchronizing is performed without assistance from a system controller or mobile units.
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58. In a short-range wireless communications network, wherein at least one mobile unit communicates with at least a portion of the network, an apparatus comprising:
means for providing short-range wireless communications within the communications network, wherein the means for providing short-range wireless communications comprises;
means for receiving a communications signal from a proximate base station unit under a wireless communications protocol, wherein the wireless communications protocol permits wireless communication with an effective range of less than 500 meters;
means for determining if the proximate base station unit has been synchronized based on the communications signal; and
means for synchronizing an internal clock based on the synchronized proximate base station, if the proximate base station unit is synchronized, wherein the synchronizing is performed without assistance from a system controller or mobile units.
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61. In a short-range wireless communications network having network access points, wherein at least one mobile unit communicates with at least a portion of the network via one or more access points, a method of synchronizing access points comprising:
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identifying an initial access point in the network;
in a first wave, wirelessly transmitting first wave synchronization data from the initial access point to a first set of access points that are positioned near to the initial access point;
synchronizing the first set of access points based on the first wave synchronization data;
in a second wave, wirelessly transmitting second wave synchronization data from at least some of the access points in the first set to a second set of access points that are positioned near to the first set of access points; and
synchronizing the second set of access points based on the second wave synchronization data.
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62. In a short-range wireless communications network having network access points, wherein at least one mobile unit communicates with at least a portion of the network via one or more access points, a method of synchronizing access points comprising:
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a first sub-domain of access points coupled to the network by way of a first power and synchronization module, wherein at least an initial access point in the first sub-domain is configured to;
establish a reference timing signal, and distribute the reference timing signal to other access points in the first sub-domain via the first power and synchronization module so that the other access points in the first sub-domain are synchronized with the initial access point;
a second sub-domain of access points coupled to the network by way of a second power and synchronization module, wherein at least one access point in the second sub-domain is configured to;
identify a neighboring one access point in the first sub-domain, synchronize with the neighboring one access point in the first subdomain, and distribute synchronization information to other access points in the second sub-domain by way of the second power and synchronization module.
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Specification