Superframe

Abstract: A communications system in which information is transmitted in successive time slots grouped into a plurality of superframes which are, in turn, grouped into a plurality of hyperframes. A remote station (120) is assigned to one of the time slots in each of the superframes for paging the remote station, each hyperframe including at least two superframes, and the information sent in the assigned time slot in one superframe in each hyperframe is repeated in the assigned time slot in the other superframe(s) in each hyperframe. Each superframe can include a plurality of time slots used for sending paging messages to remote stations, grouped into a plurality of successive paging frames, and the time slot to which the remote station is assigned is included once in every paging frame. Also, each superframe may include time slots comprising a logical channel for broadcast control information and time slots comprising a logical paging channel.

Abstract: A reservation-based wireless asynchronous transfer mode (ATM) local area network includes a system architecture of mobile nodes (MNs), each MN for communicating with various ones of the other MNs. A plurality of services is supported wherein each service has respective quality-of-service (QoS) requirements. A medium access control (MAC) layer using a reservation-based communications protocol is provided, wherein the protocol divides all MAC-based communications between a control channel and a data channel, the control channel and the data channel together making up a control-data superframe (CDS). The protocol further utilizes the control channel for allocating a bandwidth of the data channel to each service. The control channel includes a control frame during which an allocation of data payload slots of the data channel is determined according to (a) a long-term strategy corresponding to a time of service required to complete a service over multiple CDS frames and (b) a short-term strategy within a CDS frame corresponding to instantaneous data payload slot requirements for a particular service. Respective QoS requirements of each service are thus achieved.

Abstract: A method and system for controlling access to a medium in a wireless communication system. A superframe structure is defined in time domain to include a contention free period (CFP) which has at least one scheduled resource allocation (SRA), at least one management SRA (MSRA) and a contention period. An extended beacon (EB) including information about the SRA and MSRA is transmitted for. The MAC architecture reduces station battery consumption, supports higher throughput for non-real time (NRT) traffic and is more efficient for real time (RT) traffic while maintaining full compatibility.

Abstract: The IEEE 802.15.4 medium access control (MAC) protocol is an enabling technology for time sensitive wireless sensor networks thanks to its guaranteed-time slot (GTS) mechanism in the beacon-enabled mode. However, the protocol only supports explicit GTS allocation, i.e. a node allocates a number of time slots in each superframe for exclusive use. The limitation of this explicit GTS allocation is that GTS resources may quickly disappear, since a maximum of seven GTSs can be allocated in each superframe, preventing other nodes to benefit from guaranteed service. Moreover, the GTSs may be only partially used, resulting in wasted bandwidth. To overcome these limitations, this paper proposes i-GAME, an implicit GTS allocation mechanism in beacon-enabled IEEE 802.15.4 networks. The allocation is based on implicit GTS allocation requests, taking into account the traffic specifications and the delay requirements of the flows. The i-GAME approach enables the use of a GTS by multiple nodes, while all their (delay, bandwidth) requirements are still satisfied. For that purpose, we propose an admission control algorithm that enables to decide whether to accept a new GTS allocation request or not, based not only on the remaining time slots, but also on the traffic specifications of the flows, their delay requirements and the available bandwidth resources. We show that our proposal improves the bandwidth utilization compared to the explicit allocation used in the IEEE 802.15.4 protocol standard. We also present some practical considerations for the implementation of i-GAME, ensuring backward compatibility with the IEEE 801.5.4 standard with only minor add-ons.