Abstract: One feature provides a method for a client node to establish a session key with a group node by obtaining an epoch identity value associated with a current epoch, wherein obtaining the epoch identity value includes one of computing the epoch identity value based on a node real time or negotiating the epoch identity value with the group node, computing a restricted key using a shared secret key, the epoch identity value, and a group node identity associated with the group node, and executing a session key establishment protocol with the group node to derive the session key using the restricted key as a master key in the session key establishment protocol. The session key may be established between the group node and the client node even though communications between the group node and the central node is only intermittently available during the current epoch.

Abstract: Embodiments describe a varied transmission time interval in wireless communication system. According to some embodiments is a method for assigning a transmission time interval. The method can include measuring a channel condition and/or a data rate of packet communicated by at least one wireless device. Based in part on the data rate and/or channel condition information, a determination can be made whether to schedule a long transmission time interval or a short transmission time interval to the packet. A long transmission time interval can be scheduled if the channel condition is poor and/or there is a low data rate. A short transmission time interval can be scheduled if the channel condition is good and/or the data rate is high or fast. The method can be repeated for multiple wireless devices. Also included is an alternative interlacing structure that supports both long transmission time intervals and short transmission time intervals.

Abstract: For restrictive reuse, each cell (or each sector) is assigned (1) a set of usable subbands that may be allocated to users in the cell and (2) a set of forbidden subbands that is not used. The usable and forbidden sets for each cell are orthogonal to one other. The usable set for each cell also overlaps the forbidden set for each neighboring cell. A user u in a cell x may be allocated subbands in the usable set for that cell. If user u observes/causes high level of interference from/to a neighboring cell y, then user u may be allocated subbands from a “restricted” set containing subbands included in both the usable set for cell x and the forbidden set for cell y. User u would then observe/cause no interference from/to cell y. The subband restriction may be extended to avoid interference from multiple neighboring cells.

Abstract: For channel estimation in a spectrally shaped wireless communication system, an initial frequency response estimate is obtained for a first set of P uniformly spaced subbands (1) based on pilot symbols received on a second set of subbands used for pilot transmission and (2) using extrapolation and/or interpolation, where P is a power of two. A channel impulse response estimate is obtained by performing a P-point IFFT on the initial frequency response estimate. A final frequency response estimate for N total subbands is derived by (1) setting low quality taps for the channel impulse response estimate to zero, (2) zero-padding the channel impulse response estimate to length N, and (3) performing an N-point FFT on the zero-padded channel impulse response estimate. The channel frequency/impulse response estimate may be filtered to obtain a higher quality channel estimate.

Abstract: A method for implementing a sleep control that includes the steps of receiving a message from a sending block via a messaging bus, wherein the message is destined for a receiving block; determining whether the receiving block is awake; and delaying further transmission of the message until the receiving block is awake. An apparatus for performing the method is also disclosed.

Abstract: One feature provides a method for a client node to establish a session key with a group node by obtaining an epoch identity value associated with a current epoch, wherein obtaining the epoch identity value includes one of computing the epoch identity value based on a node real time or negotiating the epoch identity value with the group node, computing a restricted key using a shared secret key, the epoch identity value, and a group node identity associated with the group node, and executing a session key establishment protocol with the group node to derive the session key using the restricted key as a master key in the session key establishment protocol. The session key may be established between the group node and the client node even though communications between the group node and the central node is only intermittently available during the current epoch.

Abstract: At a mobile device, a total received power represents signals received from all access points. In order to calculate an appropriate transmit power for communication with a single access point, a mobile device determines a per sector received power level. The mobile device can ascertain a time-domain channel response from each access point pilot signal, ascertain a received digital power lever per sector from each access point pilot signal and, based in part on the digital power level, calculate a received power level from each access point. A per sector received power level can be utilized to conserve battery power and/or to reduce interference in a wireless communications network.

Abstract: Systems and methods for communicating with multiple receivers simultaneously are disclosed. In one embodiment, the method comprises applying a first adjustment to a first signal based on a first propagation path delay between a transmitter and a first receiver, combining the adjusted first signal and a second signal, and transmitting a composite signal based on the combined signal substantially concurrently to the first receiver and a second receiver.

Abstract: Embodiments describe a varied transmission time interval in wireless communication system. According to some embodiments is a method for assigning a transmission time interval. The method can include measuring a channel condition and/or a data rate of packet communicated by at least one wireless device. Based in part on the data rate and/or channel condition information, a determination can be made whether to schedule a long transmission time interval or a short transmission time interval to the packet. A long transmission time interval can be scheduled if the channel condition is poor and/or there is a low data rate. A short transmission time interval can be scheduled if the channel condition is good and/or the data rate is high or fast. The method can be repeated for multiple wireless devices. Also included is an alternative interlacing structure that supports both long transmission time intervals and short transmission time intervals.

Abstract: For restrictive reuse, each cell (or each sector) is assigned (1) a set of usable subbands that may be allocated to users in the cell and (2) a set of forbidden subbands that is not used. The usable and forbidden sets for each cell are orthogonal to one other. The usable set for each cell also overlaps the forbidden set for each neighboring cell. A user u in a cell x may be allocated subbands in the usable set for that cell. If user u observes/causes high level of interference from/to a neighboring cell y, then user u may be allocated subbands from a “restricted” set containing subbands included in both the usable set for cell x and the forbidden set for cell y. User u would then observe/cause no interference from/to cell y. The subband restriction may be extended to avoid interference from multiple neighboring cells.