Bluetooth

Bluetooth Basic idea: cable replacement Forget Plug and Play - just Play 1Mbps(Sync), 723kbps(Async) 2.4GHz ISM band 3 voice channels 8 participants in a piconet Introduced by Ericsson Laboratory Bluetooth SIG Serve as the baseline of IEEE 802.15.1 standard for WPAN

Application Examples Bluetooth

Bluetooth Application Domains Landline Data/Voice Access Points Cable Replacement Personal Ad-hoc Networks Bluetooth

Ad Hoc Networking Piconet Scatternet Share the same FHS using slotted TDD Scatternet

Radio Parameters FHSS over 79 channels of width 1MHz Modulation: GFSK 2.402 + k MHz, k = 0, …, 78 Modulation: GFSK Transmit power 0 dBm ~ 20 dBm (provided power control) i.e.) 1 mW ~ 100 mW Link range: 0.1 ~ 10m, (~100m, 20 dBm) 2.402 2.480 freq time slave master Bluetooth

Packet Transmission: FH/TDD Channel access code packet header payload 72b 54b 0-2745b 625 ms t master slave f(2k) f(2k+1) f(2k+2) Slave may transmit in a slot When master has polled the slave (ACL link) When a master sends a broadcast packet in the preceding slot When the slave alrready has a reservation for that slot (SCO link) Bluetooth

Operational States master active slave parked slave standby Links Power management Active mode Sniff mode: slave listens only at fixed interval Hold mode: does not support ACL packets, but performs scanning, paging, inquiring, or attending another piconet Park mode: gives up active member, however, stays synchronized to the channel Links ACL: asynchronous CL link for data comm. Packet switched p-t-p, p-t-mp SCO: synchnonous CO link for voice comm. P-t-p symmetric Support QoS

Protocol Stack RF Layer Baseband Layer Link Manager L2CAP FH selection: (clock, address)  FH sequence piconet creation MAC procedures Link Manager Link setup (ACL/SCO) Link control/configuration Power mgmt/Authentication L2CAP HL protocol multiplexing Segmentation/reassembly QoS management RFCOMM: Serial port emulation TCS: telephony control

Bluetooth Profile

Bluetooth Architecture Update - Core L2CAP layer connection-oriented channels and connectionless broadcast to piconet transport services for framed asynchronous and isochronous data Upper baseband layer Link Manager operates LM protocol includes Device Manager and Resource Manager transport services for unframed synchronous and isochronous data Lower baseband layer Link controller operating LC protocol packet assembly/disassembly

Upper Baseband Layer Link Manager Device Manager manages [logical] links also manages (creates, modifies, destroys) logical channels and physical links uses the LM protocol to communicate with peer link manager interacts with device manager and resource controller Device Manager scanning, paging and inquiring operations names, link keys, addresses, other local data Baseband Resource Manager contains the scheduler that allocates time to each operation and meets QoS commitments contains a resource model to check and agree to QoS settings (traffic admittance control)

L2CAP - Functional Block Channel Manager manages the creation of L2CAP channels when requested by application creates/modifies/destroys baseband logical links (when required) to support different L2CAP channel types negotiates QoS requirements with local link manager and remote channel manager L2CAP Resource Manager may check submitted traffic conforms to traffic flow specification agreed when channel created manages potential limited buffering in Bluetooth Controller schedules (orders) PDU submission to baseband

Channels and Link

Physical Channel and Link Characterized by timing and RF carrier hopping/occupancy Identified additionally by channel access code Physical link Represents a point-to-point RF connection between two devices May be active or parked

Logical Channel and Link Basic transports for data traffic between connected devices Different logical channels have behaviour suitable for data being transported such as flow control, acknowledge/repeat mechanisms and scheduling requirements Identified by LCID (logical channel identifier) field in packet header (p.k.a. AM_ADDR) Logical Link Some logical channels can support more than 1 type of traffic stream ACO can carry LMP and L2CAP logical link traffic may be interleaved subject to shared ARQn schemes Logical links defined to distinguish LMP messages, L2CAP frames (and possibly others in the future) Identified by LLID (logical link identifier) field in payload header (p.k.a. L_CH field)

Spec Update - Radio Evolution

High Priority Radio Improvements