摘要:
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.
摘要:
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.
摘要:
To reduce inter-sector interference for 'weak' users and combat a potentially large variation in interference levels observed by 'strong' and weak users, system resources (e.g., frequency subbands) available for data transmission in a system are partitioned into multiple (e.g., three) disjoint sets. Each sector in the system is assigned one subband set. Neighboring sectors are assigned different subband sets such that the subband set assigned to each sector is orthogonal to the subband sets assigned to neighboring sectors. Each sector has an assigned subband set and an unassigned subband set, which contains all subbands not in the assigned set. Weak users in each sector (which are typically strong interferers to neighboring sectors) are allocated subbands in the assigned set. Strong users in each sector are allocated subbands in the unassigned set. The weak users in each sector are then orthogonal to strong interferers in neighboring sectors.
摘要:
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.
摘要:
Systems and methods for communicating with multiple receivers simultaneously are disclosed. In one embodiment, the method comprises applying a first adjustment (405a) to a first signal (S2 (f ) ) based on a first propagation path delay between a transmitter and a first receiver, combining (410) the adjusted first signal and a second signal (S1 (f ) ), and transmitting a composite signal (S (t) ) based on the combined signal (S' (f ) ) substantially concurrently to the first receiver and a second receiver.