Abstract: An access point transmits a preemptive peg packet when it has no data to transmit in order to maintain the contiguity of its transmission timing position with respect to the timing position of other contention-free sessions (CFS) transmitted by other access points in an existing, periodic sequence. The cyclic prioritized multiple access (CDMA) method establishes the transmission timing position of contention-free sessions (CFS) between overlapping first and second wireless LAN cells contending for the same medium. Each cell includes a respective plurality of member stations. If an access point has no traffic, it will transmit a short, preemptive pegging packet and reset its backoff timer. In this manner, no gaps longer than the distributed coordination function (DCF) Interframe Space (DIFS) are left idle. This prevents other stations from using DCF contention to seize the channel, until all access points have completed one contention-free session (CFS) per periodic cycle.

Abstract: A method and system reduce interference between overlapping first and second wireless LAN cells in a medium. Each cell includes a respective plurality of member stations and there is at least one overlapped station occupying both cells. An inter-cell contention-free period value is assigned to a first access point station in the first cell, associated with an accessing order in the medium for member stations in the first and second cells. The access point transmits a beacon packet containing the inter-cell contention-free period value, which is intercepted at the overlapped station. The overlapped station forwards the inter-cell contention-free period value to member stations in the second cell. A second access point in the second cell can then delay transmissions by member stations in the second cell until after the inter-cell contention-free period expires.

Abstract: A method and system reduce interference between overlapping first and second wireless LAN cells contending for the same medium. Each cell includes a respective plurality of member stations. An inter-cell contention-free period value is assigned to a first access point station in the first cell, associated with an accessing order in the medium for member stations in the first and second cells. The access point in the first cell transmits an initial shield packet to deter other stations from contending for the medium. The access point then transmits a beacon packet containing the inter-cell contention-free period value to member stations in the second cell. A second access point in the second cell can then delay transmissions by member stations in the second cell until after the inter-cell contention-free period expires.

Abstract: A method, apparatus and computer program product for the express forwarding frames having multiple fragments are presented. A timer (NAV) is maintained at each respective node of a wireless Local Area Network (LAN). At least two fragments of a frame are designated as a Time Sensitive Quality of Service (TSQ) frame fragments to be express forwarded. A duration field of each of the TSQ frame fragments is incremented by a first predetermined time increment (DT0) before the TSQ frame fragments are forwarded. The TSQ frame fragments are transmitted when a last frame fragment is ready to be transmitted. A response is received from the second node wherein non-forwarding neighboring nodes each set their NAV according to a value equal to the duration field of the response. The second node attempts forwarding of the TSQ frame fragments when acknowledgement of receipt of the TSQ frame fragments is complete.

Abstract: A method and system reduce interference between overlapping first and second wireless LAN cells in a medium. Each cell includes a respective plurality of member stations and there is at least one overlapped station occupying both cells. An inter-cell contention-free period value is assigned to a first access point station in the first cell, associated with an accessing order in the medium for member stations in the first and second cells. The access point transmits a beacon packet containing the inter-cell contention-free period value, which is intercepted at the overlapped station. The overlapped station forwards the inter-cell contention-free period value to member stations in the second cell. A second access point in the second cell can then delay transmissions by member stations in the second cell until after the inter-cell contention-free period expires.

Abstract: An access point transmits a preemptive peg packet when it has no data to transmit in order to maintain the contiguity of its transmission timing position with respect to the timing position of other contention-free sessions (CFS) transmitted by other access points in an existing, periodic sequence. The cyclic prioritized multiple access (CPMA) method establishes the transmission timing position of contention-free sessions (CFS) between overlapping first and second wireless LAN cells contending for the same medium. Each cell includes a respective plurality of member stations. If an access point has no traffic, it will transmit a short, preemptive pegging packet and reset its backoff timer. In this manner, no gaps longer than the distributed coordination function (DCF) Interframe Space (DIFS) are left idle. This prevents other stations from using DCF contention to seize the channel, until all access points have completed one contention-free session (CFS) per periodic cycle.

Abstract: A cyclic prioritized multiple access (CPMA) method is disclosed which includes Fixed Deterministic Post-Backoff. Fixed deterministic post-backoff reduces conflicts between access points of overlapping cells. Contention-free sessions (CFSs) can be generated, one from each overlapping cell. Each active access point engages in a fixed deterministic post-backoff. A fixed deterministic backoff delay (Bkoff times a fixed number of idle time slots) is used by all access points, with the value of Bkoff being greater than the number of overlapping cells. The Bkoff should be large enough to enable the traffic that needs to be accommodated by the channel. Each access point has a backoff timer that is counted down using the shortest interframe space possible, typically the Priority Interframe Space (PIFS). A contention-free session (CFS) is initiated when the backoff timer expires, and it is then reset to the value of Bkoff to start a new cycle.

Abstract: A technique is disclosed for dealing with transmissions between telecommunications stations on a shared-communications channel that avoids some of the costs and disadvantages for doing so in the prior art. The present invention introduces transmission rules that alleviate timing constraints. By following the transmission rules in accordance with the illustrative embodiment of the present invention, stations exchanging data with each other can prepare frames for transmission far enough in advance to overcome timing constraints.

Abstract: A method, apparatus and computer program product for transmitting broadcast/multicast data in a wireless network, is presented. The network includes either a plurality of multi-radio nodes, or a plurality of single-radio nodes, or a mix of multi-radio and single-radio nodes and the network further includes a control channel and at least one data channel. Transmission of the broadcast/multicast data occurs either on the control channel or on a data channel.

Abstract: A method, apparatus and computer program product for coordinating adjacent channel transmissions on multiple-radio nodes is presented. A Maximum Channel Occupancy Duration (MCOD) limit for a length of an overall transmit period is defined. A set of timers (NNAV) for each neighbor node is maintained, each of said NNAV including a first timer (CTSNNAV) for the channel which, if set, indicates the maximum duration of a transmission to said neighbor node and a second timer (RTSNNAV) for a channel which, if set, prevents the neighbor node from authorizing a transmission the channel.

Abstract: Spectrum monitoring measurements are made by microcell base stations in a layered cellular network, while not serving calls or engaged in processing calls. The microcell base station transmits a first control message from to a microcell mobile station, to increase the duration for the mobile station to reside in the camping state on a control channel of the microcell base station. The microcell base station transmits a second control message from the microcell base station to the microcell mobile station, to increase the duration for the mobile station to reside in a call origination state while attempting to access a control channel of the microcell base station. Then, to perform the spectrum monitoring measurement, the base station's transmitter is turned off, the receiver is retuned to the frequency to be monitored, a signal strength measurement taken on that frequency, the receiver is retuned back to its assigned frequency, and the transmitter is turned back on, all in a short time interval.

Abstract: A method of providing power management in a Wireless Local Area Network (WLAN) is presented. The method includes receiving a Traffic Indication Map (TIM) at a station, indicating the presence of buffered frames, associated with any AC, for the station at an Access Point (AP). The method further includes sending, by the station, one of an uplink data frame if one is buffered, and a null frame to retrieve the buffered frames from said AP. The station remains awake to receive frames from the AP until a downlink frame is received containing an indication that it is the last frame to be transmitted in the service period. The method may further include determining at the end of service period whether there are more frames remaining buffered for the station at the AP.

Abstract: A novel method and apparatus for coping with lost acknowledgements from power-saving stations in local-area networks are disclosed. In particular, the illustrative embodiment modifies the access point's and power-saving stations' protocols to prevent repeated lost acknowledgements from occurring. An access point, after transmitting the final downlink frame of a sequence to a station and receiving an acknowledgement from the station, transmits a “double acknowledgement” to the station. A power-saving station, after receiving the final downlink frame of a sequence and transmitting an acknowledgement to the access point, stays awake until one of the following occur: (i) the station receives a double acknowledgement, (ii) the station observes a frame transmitted from the access point to another station, or (iii) the station observes that the shared-communications channel of the local-area network is idle for a particular time interval.

Abstract: A method, apparatus and computer program product for providing adjacent channel interference avoidance is presented. A first set of channels and a second set of channels of a Radio Frequency (RF) spectrum used by the wireless network are defined, the first set having a plurality of channels and the second set having a plurality of channels, and wherein the first set and the second set have mutually non-adjacent channels. A channel in the first set is designated as the control channel, the control channel being non-adjacent to channels in the second set, and used by all nodes of the wireless network. The channels in the first spectrum are utilized for the control channel and for data channels for unicast transmissions between single-radio nodes. The channels of the second set are utilized as data channels for unicast and multicast transmissions by multi-radio nodes.

Abstract: A method and apparatus are disclosed that enable taking into consideration the variation in channel occupancy of a particular terminal or terminals during the call admission process. A channel utilization manager accounts for the probabilistic nature of the call admission decision by using a pre-determined, statistically justified value to represent the channel occupancy. The “per-call” channel occupancy value is determined by a number of factors, including the shared-communications channel data rate. Channel occupancy is incorporated into one or more cumulative distribution functions (CDF), which are evaluated by the channel utilization manager as part of the call admission process. In turn, each channel-occupancy CDF of a shared-communications channel can be generated from a CDF of the terminals' data rates on that channel, which data rates can be determined analytically or empirically.

Abstract: Overlapped wireless LAN cells in a medium have an equal chance at establishing a session on the medium. A first member station in the first cell transmits a timing packet containing a timestamp value, which is received at a second member station in the second cell. This synchronizes member stations in the first and second cells to interrupt transmissions at a global channel release instant corresponding to the timestamp value. The member stations in the first and second cells then have the opportunity to contend for access to the medium following the global channel release instant, using a slotted CSMA/CA access method. Each of the member stations in the first and second cells has a superframe clock that is synchronized based on the timestamp value, thereby establishing a periodic global channel release instant during each of a plurality of periodic superframes. The member stations can then periodically interrupt transmissions at the periodic global channel release instant to contend for the medium.

Abstract: A method and apparatus for maintaining a connection between a wireless transmit/receive unit (WTRU) and a blanket wireless local area network (BWLAN) are described. An inter-working function (IWF) entity in a given network access point (NAP) of the BWLAN maintains lists of WTRUs in respective states. Furthermore, the given NAP maintains a list of neighbor NAPs, and operates in accordance with a selected WTRU mobility protocol. The states may include a “not aware” (NA) state in which the given NAP is actually not aware of a particular WTRU, an “active transmit” (AT) state in which the given NAP is actively transmitting to a particular WTRU, and a “neighbor range” (NR) state for WTRUs indicated in an update report from neighbor (URN) message that the given NAP was not aware of. The WTRU mobility protocol may be a push mobility protocol or a poll mobility protocol.

Abstract: A staggered startup method and system for a cyclic prioritized multiple access (CPMA) system reduce interference between overlapping first and second wireless LAN cells contending for the same medium. Each cell includes a respective plurality of member stations. A first member station in the first cell coordinates a periodic sequence of first contention-free sessions. Each contention-free session includes multiple bursts with other member stations in the first cell. The first member station retains control of the medium by using interframe spaces sufficiently short between the bursts so that the multiple bursts appear to contending stations to be a single instance of activity in the medium during a session until an end of a session. A second member station in the second cell listens to the activity in the medium and detects an end to one of the first contention-free sessions indicated by an interval longer than a PIFS idle interval following an end to the activity in the medium.

Abstract: Overlapped wireless LAN cells in a medium have an equal chance at establishing a session on the medium. A first member station in the first cell transmits a timing packet containing a timestamp value, which is received at a second member station in the second cell. This synchronizes member stations in the first and second cells to interrupt transmissions at a global channel release instant corresponding to the timestamp value. The member stations in the first and second cells then have the opportunity to contend for access to the medium following the global channel release instant, using a slotted CSMA/CA access method. Each of the member stations in the first and second cells has a superframe clock that is synchronized based on the timestamp value, thereby establishing a periodic global channel release instant during each of a plurality of periodic superframes. The member stations can then periodically interrupt transmissions at the periodic global channel release instant to contend for the medium.

Abstract: Quality of Service (QoS) support is provided by a Tiered Contention Multiple Access (TCMA) distributed medium access protocol that schedules transmission of different types of traffic based on their service quality specifications. In one embodiment, a wireless station is supplied with data from a source having a lower QoS priority QoS(A), such as file transfer data. Another wireless station is supplied with data from a source having a higher QoS priority QoS(B). Each wireless station can determine the urgency class of its pending packets according to a scheduling algorithm. There are several urgency classes which indicate the desired ordering. Pending packets in a given urgency class are transmitted before transmitting packets of a lower urgency class by relying on class-differentiated urgency arbitration times (UATs), which are the idle time intervals required before the random backoff counter is decreased.