Peer Aware Communication MAC Frame Structure <month year> doc.: IEEE 802.15-<doc#> Peer Aware Communication MAC Frame Structure Seong-Soon Joo*, In-Hwan Lee, Hyo-Chan Bang ETRI <author>, <company>

MAC Frame Structure Two layered MAC frame structure Synchronization Interval fixed number of TDMA subslots (eg. 12 usec long, SI = 8,334 subslots = 100.08ms) pre-assigned subslots for synchronization, peer discovery, peer group control, contention access data channel, contention free data channel slot Superframe and Cyclic Superframe superframe is comprised of number of sync intervals the usage of slots of superframe is configured according to the service type assign idle period among synchronization, discovery, control/groupcast, connectionless link, connection-oriented link period cyclic superframe = active period(n*superframe) + inactive period(m*superframe of idle period) Superframe (ex. active period ) Sync Period Discovery Period Control Period CL Period CO Period Sync Period Discovery Period Idle Period Idle Period CO Period subslot Sync Slot Discovery Slot Control Slot CA-Data Slot CF-Data Slot Sync Slot Discovery Slot Control Slot CA-Data Slot CF-Data Slot Synchronization Interval Synchronization Interval cyclic superframe active inactive s d c CL CO s d c CL s d s d s d s d

MAC Superframe superframe types for data phase of application services type 1 (uni-directional connectionless message transmission) advertise or discover with transmitting data single Sync Interval (sync – discovery – idle – CL – idle period) type 2 (bidirectional connectionless message transmission) discover request and response with transmitting data two Sync Interval (sync – discovery – control– CL – idle period)-(sync – discovery – idle – CL – idle period) type 3 (delay tolerant message transmission) establish a contention access link after discovery (sync – discovery – control – CL – idle period) type 4 (mixed type of traffic) support mixed type of traffic two Sync Interval (sync – discovery – control – CL – CO period)-(sync – discovery – idle – CL – idle period) type 5 (reliable message transmission) establish a guaranteed access link after discovery (sync – discovery – control – idle – CO period) type 6 (open configurable superframe) select length of superframe and slot usage of sequentially appeared slots of sync intervals advertised by superframe structure Information Element transmission priority of slots among service types type 6 > type 5 … > type 1

MAC Cyclic Superframe configuration of MAC cyclic superframe service type, number of active superframe, number of inactive superframe given by higher layer through MAC layer primitives usage of MAC cyclic superframe in service phase discovery phase : discovery slots of inactive superframe are also used peering phase : control slots of inactive superframe are also used data phase : follow the active superframe configuration cyclic superframe example service type 4, active period 1, inactive period 1 (sync – discovery – control – CL – CO period)-(sync – discovery – idle – CL – idle period) cyclic superframe active inactive discovery s d s d s d s d s d s d peering s d c s d c s d c s d c s d c s d c data s d c CL CO s d CL s d s d s d c CL CO s d CL

Distributed Resource Reservation addressing link resource indicates two ends of a link by peer link IDs peer link ID = peer device ID (12bits) + peer link ID (4bits) assign resource for a link CAP : superframe sequential ID + CL period sequential ID CFP : superframe sequential ID + CO period sequential ID + slot ID distributed resource reservation during peering reservation CL period of service type 3, 4 assign CL period of a cyclic superframe sequentially in the order of peering requests reservation CO period of service type 4, 5, 6 source peer device of an uni-directional link before reserving CFP slots, scan neighbor’s control slot select superframe, CO period, and slots based on the hashed peer link ID request to reserve slots to other end peer device by sending peering request destination peer device of an uni-directional link receive peering request with assigned resource for a link check available slots by scanning neighbor’s control slot send ack or adjusted slot assignment to source of a link

Distributed Interference Avoidance interference avoidance among multiple peer groups access control to multiple peer groups as a participant follow the priority of service types among peer groups access control as an initiator select start time of the cyclic superframe opportunistic transmission based on designed statistical access interference avoidance example coexist multi peer groups service type 3 (active 2, inactive 0) peer group service type 4 (active 1, inactive 1) peer group apply shorter backoff to access CL period of service type 4 cyclic superframe service 3 peer group data phase s d c CL s d c CL s d c CL s d c CL s d c CL cyclic superframe service 4 peer group data phase s d c CL CO s d CL s d s d s d c CL CO s d CL

PAC MAC Frame Formats frames MAC frame header frame control : version, frame type, dest link ID/src link ID/IE indicator Advertise Req, Discover Req/Resp, Peer Req/Resp, DePeer Req/Resp, RePeer Req, Data peer group ID : peer group service type (3bits) + local group ID (5bits) peer link ID : peer device ID (12bits) + peer link ID (4bits) peer group authenticator MAC frame information elements type, length, value peer group information element : with control & management commands MAC frame payload MAC frame tail frame check sequence frames advertise, discover req. : header (3B) + payload (var) + tail (2B) peer req./resp : header (9B) + IE (4B) + tail (2B) data : header (5B) + IE (3B) + payload (var) + tail (2B) Octets: 2 1 0/2/8 0/2 0/variable 2 Frame Control Peer Group Identifier Destination Peer Link ID Source Peer Link ID Peer Group Authenticator Peer Group Information Element Frame Payload Frame Check Sequence Peer Link Addressing fields MAC Frame Header MAC Frame Information MAC Frame Payload MAC Frame Tail

Frame Filtering at MAC Layer the first frame filtering filtering all the frame check the peer group service type if not matched, discard the second frame filtering filtering all the frame except advertise, discover req., discover resp. frame check the local group ID the third frame filtering check the peer device ID and peer link ID if matched without Relaying IE, forward frames to higher layer the fourth frame filtering check Relaying IE if frame arrives on correct link, relay frames to outward device by transmitting a frame on outward link