摘要:
In a distributed-control cognitive radio network, each secondary user (200) in a network broadcasts parameters (125) that indicate the minimum quiet-period sensing demand for regular quiet-periods that the device requires for reliable detection of a primary user (290). Each device (200) in the network adjusts its quiet-period sensing rate to accommodate the highest minimum sensing demand (155, 160), thereby providing optimal efficiency relative to quiet-period support while assuring that all devices (200) in the network are provided at least their minimum quiet-period sensing demand (150). Both the interval between regular quiet-periods and the duration of these quiet-periods are negotiated among the devices on the network (155). A quiet-period index (140) is used to synchronize all of the devices to a common time base. Techniques are also provided for efficient coordination of on-demand quiet-period requests, and for supporting different quiet-period schedules for multiple classes of primary users.
摘要:
A flexible wireless system and method that support both centralized and distributed modes of MAC protocols, use a new recurring MAC superframe (m) comprising: a beacon period (BP), a data/sense/sleep period (DSSP) for data selective communication, sleep and channel sensing for detecting primary users in cognitive systems; and a signaling window (SW) used for exchanging network entry messages and channel reservation requests, the system including beacon operation, a peer beacon device in distributed mode and a master beacon device in centralized mode which are used to selectively participate in the beacon operation, as well as a slave beacon device associated with the master device. The system may employ controlled channel access for the beacon period, the channel access being reservation based. The invention provides a unified MAC protocol that can be adopted in the standards, and supports flexible operation in distributed mode or centralized mode, and seamless transfer from one to the other.
摘要:
The present invention is a system, apparatus, and method for a “Priority” field that is included in the information transmitted by an Access Point (AP) (801i) about its neighbor APs (801i) and the network service providers (SPs) that it supports. A “Priority” field (103i-6 154i.2 203.i.2 233 266) is included in at least one of a Neighbor Report element (100), an AP Channel Report element (150), and a service provider's information element (200 230 260). The service provider priority field (203.i.2 233 266) is contained in any protocol frame transmitted by the AP (801i) that contains information about one or more service providers that it supports. The “Priority” field (103i.6 154-i.2 203.i.2 233 266) contains a numeric value or a symbolic indicating a recommendation from the AP (801i) concerning which AP/APs and service provider(s) SP/SPs for a STA (802j) to scan first or access in an eventual roaming/accessing process. For roaming/accessing purposes, more than one neighboring AP (801i) can have the same priority value and not all the APs (801i) that are neighbors or support SPs necessarily have the same priority value.
摘要:
A system and method for wireless BANs and short-range wireless networks that support heterogeneous devices and applications are disclosed. In one example embodiment, a method of implementing a MAC superframe structure for short-range wireless networks includes transmitting multiple beacon slots (102) during a beacon period (404) wherein the multiple beacon slots (102) include one or more simplified beacon slots associated with one or more simple devices (102), and transmitting payload data during a data transfer period (410) substantially following the beacon period (404) and wherein the data transfer period (410) includes one or more RCA periods (412) associated with the one or more simple devices (102) for transmitting and/or receiving the payload data associated with the one or more simple devices (102) upon receipt of the indication that the RCA period (412) is present in the one or more simplified beacon slots associated with the simple devices (102).