Abstract: The station does not wake up for the beacon TIM if there is periodic uplink data with period less than or equal to the tolerance for downlink delay. If the station has no uplink data for at least a service interval (period of the stream), it wakes up to listen to the TIM. It continues to do so until either uplink or downlink data arrives. If the TIM indicates downlink data buffered, and if the station continues to have no uplink data, it starts waking tip at the service interval and sends null frames uplink, in order to signal that it is awake and ready to receive downlink data. If uplink data is generated, the station will send the uplink frame instead of the null frame.

Abstract: A method, apparatus and computer program product for providing collision avoidance and/or channel capture is presented. A timer (NAV) for a channel which, if set, prevents the node from transmitting on the channel is maintained at a station. A determination is made whether a duration of a transmission response (CTS) has expired. The NAV is cleared when the channel is idle for a predetermined time interval and the flag is clear, and the NAV is not cleared when the flag is set.

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 technique is disclosed that enables a voice call to be initiated on the Public Switched Telephone Network and directed to a VoIP telephone on the Internet without the association of a unique telephone number to the VoIP telephone. In accordance with the illustrative embodiment of the present invention, a user who has a PSTN wireline telephone or a PSTN cell phone associates his or her VoIP telephone with the telephone number of the PSTN wireline telephone or the PSTN cell phone or with both numbers. In other words, the VoIP telephone is not assigned its own telephone number but shares the telephone number of the PSTN telephones of its owner.

Abstract: A novel method for coordinating the delivery of frames to and the receipt of frames from a power-saving station in a wireless local-area network (LAN) is disclosed. The illustrative embodiment establishes a wake-up schedule for a power-saving station based on a temporal period and temporal offset that reduces the frequency with which multiple stations in a network wake up simultaneously, thereby reducing traffic delays and power consumption. The illustrative embodiment is particularly well-suited to networks with traffic that has delay/jitter quality-of-service (QoS) requirements (i.e., voice calls, videophone calls, etc.).

Abstract: A method, apparatus and computer program product for providing start-to-finish reservations in distributed MAC protocols for wireless LANs. Each node maintains a corresponding time period (NAV) during which the node must refrain from transmitting on a channel of a plurality of traffic channels. Each NAV is set by detecting a reservation request (RRQ) or a reservation response (RRS), each corresponding NAV comprising the larger of a RRQ NAV value and a RRS NAV value. Each node declines to reserve a traffic channel while the NAV is non-zero, and declines to transmit on a channel when the node detects the occurrence of a transmission on the channel or that the NAV is non-zero. The RRQ NAV is reset while a corresponding RRS NAV is decremented when a reservation is cancelled, and the RRS NAV is reset while a corresponding RRQ NAV is decremented when the reservation time period expires.

Abstract: Quality of Service (QoS) support is provided by means of 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, such as file transfer data. Another wireless station is supplied with data from a source having a higher QoS priority, such as voice and video data. Each wireless station can determine the urgency class of its pending packets according to a scheduling algorithm. 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, which are the idle time intervals required before the random backoff counter is decreased.

Abstract: A method, apparatus and computer program product for using a single-radio node and a multi-radio node in a wireless network having a control channel and at least one data channel is presented. One radio of the multi-radio node is kept tuned to the control channel. The single-radio node and the multi-radio node release the control channel at a predetermined time. Further, the data channels used by the single-radio nodes are released at the predetermined time. In such a manner single-radio and multi-radio nodes can co-exist harmoniously in wireless networks with increased bandwidth utilization and efficiency.

Abstract: A method and apparatus for providing channel access coordination in a BSS or a wireless mesh is presented. A control channel is assigned to a control radio. At least one data channel is assigned to at least one data radio. Control signals are transmitted and received on the control channel, and data is transmitted and received on the at least one data channel. Acknowledgements for the data are received on the control channel. A node having a plurality of radios can transmit and receive traffic on different data channels simultaneously.

Abstract: A method, apparatus and computer program product for performing dynamic channel assignment in wireless ad hoc networks (wireless mesh and infrastructure BSSs) is presented. A fixed channel assignment order is determined for each link of the network, the fixed channel assignment order enabling simultaneous transmission without co-channel interference. A preference order is loaded for a node, the preference order derived from the fixed channel assignment order. A channel is selected in accordance with the preference order when a node is ready for transmission. A determination is made whether the selected channel is available, and when the selected channel is available then the node transmits on the channel and when the selected channel is not available then a next channel in the preference order is selected for the node and the determination regarding whether the selected channel is available is repeated.

Abstract: An apparatus and methods for handling emergency message frames (e.g., “911” call frames, etc.) sent by a station in a wireless local-area network are disclosed. The illustrative embodiment increases the probability with which an emergency message frame is accorded the singularly highest quality-of-service by modifying one or more IEEE 802.11e parameters (e.g., back-off contention window length, Arbitration Inter-Frame Space [AIFS], etc.) for a station or access point that transmits an emergency message frame.

Abstract: An apparatus and methods for handling emergency message frames (e.g., “911” call frames, etc.) sent by a station in a wireless local-area network are disclosed. The illustrative embodiment increases the probability with which an emergency message frame is accorded the singularly highest quality-of-service by modifying one or more IEEE 802.11 e parameters (e.g., back-off contention window length, Arbitration Inter-Frame Space [AIFS], etc.) for a station or access point that transmits an emergency message frame.

Abstract: An access method for periodic contention-free sessions (PCFS) reduces interference between overlapping first and second wireless LAN cells contending for the same medium. Each cell includes a respective plurality of member stations and an access point (AP) station. The access method for periodic contention-free sessions (PCFS) includes a fixed cycle time that reduces conflicts with PCFS from other cells. The PCFS from several cells are repeated in cycles of cycle period (CP), which is the contention-free period (CFP) of an access point times a factor that is a function of the number of overlapping cells. Periodic contention-free sessions (PCFSs) are generated, one from each overlapping cell. PCFS transmission attempts occur at the fixed specified time spacing following the start of the previous cycle. Each active AP sets a timer at CP and a PCFS is initiated when the timer expires. The timer is then reset and starts a new cycle.

Abstract: A method, apparatus and computer program product for the express forwarding are presented. A node attempts to transmit a frame designated as a Time Sensitive Quality of Service (TSQ) frame to be express forwarded from a first node to a second node of a plurality of nodes. A collision is detected involving the TSQ frame while attempting to transmit the TSQ frame. A retransmission of the TSQ frame is attempted without waiting a predetermined back off period.

Abstract: The present invention provides a technique for directly calling telephones via a shared telephone number, which telephones do not have telephone numbers in the address space of the Public Switched Telephone Network. This is particularly useful for visitors and guests who are, for example, temporarily at a hotel, school campus, or business.

Abstract: A technique is disclosed to optimize the call admission control algorithm that governs a shared-communications channel, in which the algorithm accounts for the levels of mobility, on an individual basis, of one or more terminals that need to use the channel. Instead of determining the variation in the distribution of supported data rates aggregated across multiple terminals—which can result in a greater variance in the call admission criterion—the technique of the illustrative embodiment tracks the variation in the distribution, for each terminal, of the data rates for that terminal. In short, the technique of the illustrative embodiment accounts for the variance in data rates that is attributed to the mobility of individual, representative terminals and not to the variance that is attributed to the spatial distribution of multiple terminals.

Abstract: An apparatus and method for informing a coordinator of the particular characteristics of a periodic traffic source are disclosed. A station that generates a periodic traffic stream encodes the temporal period and temporal offset of the traffic stream within a quality-of-service (QoS) traffic specification, and transmits the traffic specification with a poll request. The coordinator, upon receiving a polling request, processes the associated traffic specification and, via appropriate decoding logic, determines whether the requesting station generates periodic traffic, and if so, the temporal period and temporal offset of the traffic stream. The coordinator subsequently can establish, based on the temporal period and temporal offset, a polling schedule that minimizes the delay between (i) the station generating a frame, and (ii) the station transmitting the frame (and thus the destination receiving the frame).

Abstract: A method, apparatus and computer program product for providing a prioritized MAC protocol for a WLAN or wireless mesh using a time filtering technique wherein a time limit (Advanced Interval For Reservation or AIFR) is imposed on the time prior to the expiration of data channel's NAV when a data channel is considered ‘almost idle’. The same AIFR limit applies to all CC-RTS of the same priority, and a higher priority CC-RTS will have a longer AIFR.

Abstract: A novel method for coordinating the delivery of frames to and the receipt of frames from a power-saving station in a wireless local-area network (LAN) is disclosed. The illustrative embodiment establishes a wake-up schedule for a power-saving station based on a temporal period and temporal offset that reduces the frequency with which multiple stations in a network wake up simultaneously, thereby reducing traffic delays and power consumption. The illustrative embodiment is particularly well-suited to networks with traffic that has delay/jitter quality-of-service (QoS) requirements (i.e., voice calls, videophone calls, etc.).

Abstract: As is reflected in the disclosed method and apparatus, the present invention is a technique to account for the variation in channel occupancy of a particular terminal or terminals during the call admission process. Instead, 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.