BOSS Implementation

1. Fundamental Features

• Tx Packets. 
• Rx Packets from specific sender. 
• Set Bluetooth ID to each ubertooth device
  • Manually set address. 
  • Auto generate ID.
• Code packet generator:
  • Control PDU 
    • ADV_IND. 
    • ADV_DIRECT_IND 
    • ADV_NONCONN_IND 
    • ADV_SCAN_IND 
    • SCAN_REQ. 
    • SCAN_RSP. 
    • CONNECT_REQ 
  • Data PDU 
    • LL Data PDU (empty one)
      • LLID: 01
      • Length: 00000
      • Missing setting the received values of SeqNum & nextSeqNum from both master and Slave.
• Received Pkts:
  • set correct Adresses, i.e., AdvAdr & initAdr 
  • set timing parameters. 

2. BLE States

2.1 Advertising

1. Inform host of "Entering Advertising State"
2. Introduce the Logic in initAdvertisingStateBoss() in bluetooth_rxtx.c
3. Calculate advInterval, advDelay, and T_advEvent.
4. Set channel index [37, 38, 39].
5. Send an Advertising packet, i.e., ADV_IND.
6. Wait for CONNECT_REQ request for T_advEvent period to enter Connection State
7. IF no CONNECT_REQ, move to next adv channel and repeat sending Advertising packet.

2.2 Initiating

1. Inform user of "Starting Initiating state".
2. Introduce the Logic in initInitiatingStateBoss() in bluetooth_rxtx.c.
3. Insert device addresses:
   1. InitA: current device BT ID.
   2. AdvA: device sending advertising pkts.
4. Receive advertising pkts from AdvA.
5. Generate CONNECT_REQ pkt.
6. Transmit CONNECT_REQ.
7. Move to Connecting state.
8. Inform host of Entering Connection State

2.3 Connection

• Inform user of "Entering Connection state as a YY with device XXX", where YY is a master or slave and XXX is the ID of the other party.
• Introduce the Logic in initConnectionStateBoss() in bluetooth_rxtx.c

2.3.1 Channel Selection Algorithm

• Channel Map:
  • used channels: used data channels for the connection. min number is 2.
  • unused channels: unused data channels in this connection.
• Assume the channel map has all channels available. CAN BE RELAXED LATER.

• Channel Selection Algorithm:
  • Calculate unmapped channel index.
  • mapping the index to a data channel from the unused set.
• Parameters:
  • unmappedChannel: unmapped channel index for the current connection event.
  • lastUnmappedChannel: unmapped channel index of previous connection event.
  • remappingIndex: in case of selection a channel from the unused map, this is used to remap the index to one of the used channels.
  • numUsedChannels: number of used channels in the channel map.

unmappedChannel = (lastUnmappedChannel + hopIncrement) mod 37
 IF unmappedChannel NOT IN used Channel map
   remappingIndex = unmappedChannel mod numUsedChannels
 END
 lastUnmappedChannel = unmappedChannel of previous connection, 0 in initial connection

2.3.2 Master & Slave

• connEventCounter
  • 16-bit counter.
  • Set to zero (0x0000) on first connection event
  • master: incr on sending a new connection event
  • slave: incr for each connection event.

2.3.3 Master

Coming from Initiating state.

• Calculate connSupervisionTimeout.
• If connSupervisionTimeout times out without receiving a packet.
  • Move to STANDBY State.
• Calculate transmitWindowOffset and transmitWindowSize.
• Reset connSuperVisionTimeout
• Generate first Data PDU.
• Select a data channel .
• wait for transmitWindowOffset+1.25ms.
• send first data pkt within transmitWindowSize
• wait for ""T_IFS" for a response from slave
  • YES, move to next channel and send next pkt after connInterval
  • NO, move to STANDBY state

2.3.4 Slave

Coming from Advertising state.

• Notify Host: "Slave connection is created!".
• Reset connSuperVisionTimeout.
• Choose a channel index.
• Listen to a packet within transmitWindowSize.
  • YES
    • If FIRST Then, set anchor point and timing parameters.
    • respond
    • switch channel.
  • No
    • Attempt to Rx in other TransmitWindow till the end of connInterval.
    • switch channel,
    • Expect for a transmitWindowSize. If still No, move to STANDBY State.

2.4 Scanning

1. Passive

2.5 Standby

1. Inform user of "Entering Standby State".
2. Terminate the host request.