1. CS 414 Indian Institute of Technology, Bombay CS 414 802.15.1

2. CS 414 Indian Institute of Technology, Bombay User Scenarios ● Several desktop computer peripherals – mouse, keyboard, headset, speakers, joystick... – each has ● different type of cable (wire) ● different type of connector/plug ● Meeting or classroom discussions – need to exchange files/data – exchange of images/audio across cell phone ● Tetherless cell-phone ear-pieces

3. CS 414 Indian Institute of Technology, Bombay Requirements ● Small local wireless network – limited range (~10 m) ● Low cost – every device will need one ● Ad-hoc – infrastructure setup adds cost and constraints ● 802.15.1/Bluetooth provides above

4. CS 414 Indian Institute of Technology, Bombay

5. Bluetooth Radio Link ● Operates in the 2.4 Ghz ISM band – 2.402 GHz to 2.4835 GHz – same as 802.11 b/g, 802.15.4 – 79 channels of 1MHz each ● 2.402 Ghz + K Mhz k = 0 to 78 – FHSS over the 79 channels ● 1600 hops / s – GFSK modulation at PHY... 1Mhz 1 2 3 79 83.5 MHz 1MHz

6. CS 414 Indian Institute of Technology, Bombay Piconet ● A collection of Bluetooth devices synchronized to the same hopping pattern M S SBSB S P P S SBSB P M: Master S: Slave P: Parked SB: Stand-by 3-bit address field Limit of 7 slaves AMA: Active Member Address (3-bit) PMA: Park Member Address (8-bit) State of each device Every device can be M/S

7. CS 414 Indian Institute of Technology, Bombay Piconet ● Master decides hopping pattern ● Master can connect to 7 slaves ● Capacity of each piconet < 1Mbps ● Master always transmits in even slot ● Slave in odd slot

8. CS 414 Indian Institute of Technology, Bombay Type of Connections ● Synchronous Connection Oriented (SCO) Link – Full-duplex link – Reserved slots (alternate between M and S) ● Asynchronous Connection Link (ACL) – Unscheduled – Master sends data + polls slave – Slave replies

9. CS 414 Indian Institute of Technology, Bombay FH/TDD (single-slot) One packet per slot

10. CS 414 Indian Institute of Technology, Bombay FH/TDD (Multi-Slot)

11. CS 414 Indian Institute of Technology, Bombay Connection Management Standby InquiryPage Connected Transmit data Park Hold Sniff No TDD, Random Slots Synch and Hopping Pattern

12. CS 414 Indian Institute of Technology, Bombay Device States ● Standby: Device not part of piconet ● Sniff: Low-power state – Listens to master at reduced rata – Keeps its AMA ● Hold – No ashyncronous transfer only sychronous – Retains AMA ● Park – Gives up AMA, gets PMA – Periodic wakeup for broadcast data and re-synch

13. CS 414 Indian Institute of Technology, Bombay ScatterNet ● One Piconet in 80MHz with capacity less than <1Mbps ● Efficient ?

14. CS 414 Indian Institute of Technology, Bombay ScatterNet M S S S M S S S ● Multiple piconets in overlapping regions ● FH-CDMA – each piconet has its own code (spreading sequence)