BYR Achieve · 镜像论坛

[恭喜开版]Bluetooth协议keyword Bluetooth ad-hoc piconets WPAN = wireless personal area networks POS = personal operating space user scenarios connection of peripheral devices support of ad-hoc networking bridging of networks Bluetooth operates on 79 channels in the 2.4 GHz ISM band with 1 MHz carrier spacing. apply FHSS for interference mitigation FH-CDMA for separaton of networks piconet A piconet is a collection of Bluetooth devices which are synchronized to the same hopping sequence. M = master one device determines the hopping pattern in the piconet S = slave all the other connected to the master up to seven simultaneous slaves AMA = active member address (3-bit) all active devices are assigned a AMA P = parked can not actively participate in the piconet, but are known and can be reactivated within some milliseconds more than 200 devices can be parked PMA = parked member address (8-bit) all parked devices use a PMA SB = standby do not need an address the hopping pattern is determined by the device ID, a 48-bit worldwide unique identifier the phase in the clock pattern is determined by the master's clock All users within one piconet have the same hopping sequence and share the same 1 MHz channel. scatternet many piconets with overlapping coverage can exist simulaneously As soon as a master leaves a piconet, all traffic within this piconet is suspended until the master returns. protocol stacks core specifications radio specification of the air interface baseband description of basic connection establishment, packet formats, timing, and basic QoS parameters linked manager protocol link set-up and management between devices including security functions and parameter negotiation logic link control and adapatation protocol (L2CAP) adaptation of higher layers to the baseband service discovery protocol device discovery in close proximity plus querying of service characteristics profile specification cable replacement protocol RFCOMM RFCOMM = radio frequency comm. TCS BIN = telephony control protocol specification - binary HCI = host controller interface between the baseband and L2CAP provide a command interface to the baseband controller and link manager BNEP = Bluetooth network encapsulation protocol OBEX = Object exchange Calender and business card objects (vCalender/vCard) can be exchanged using the object exchange protocol AT = attention sequence SDP = service discovery protocol radio layer bluetooth transceivers use Gaussian FSK for modulation Power Class 1 (100mW) Power Class 2 (2.5mW) Power Class 3 (1mW) baseband layer TDD 1-slot/3-slot/5-slot packets baseband packet format (bits) access code 68(72) preamble 4 sync. 64 (trailer 4) packet header 54 AM address 3 type 4 flow 1 ARQN 1 SEQN 1 HEC 8 payload (0-2744) Up to 343 bytes physics links two types SCO = synchronous connection-oriented link ACL = asynchronous connectionless link FEC = forward error correction CVSD = continuous variable slope delta payload header link manager protocal authentication, pairing and encryption synchronization capability negatiation quality of service negotiation power control link supervision state and transmission mode change low power state sniff state keeps its AMA hold state park state release AMA and recieve PMA all PDUs sent to parked slaves are broadcast L2CAP L2CAP provides three different types of logical channels that are transported via the ACL between master and slave connectless connection-oriented signaling CID = channel identifier PSM = protocol/service multiplexor 1 : SDP 3 : RFCOMM 5 : TCS - BIN > 4096 : assigned dynamically security SDP profiles basic profile addition profile IEEE 802.15 ____________________________________________ bupt.sice.ce@gmail.com