Packet Layout

Header:

• Byte 0, most 4 significant bits: Packet Information
  • LL_ACK_FLAG 0x10
  • LL_RESENT_FLAG 0x20
  • LL_RELIABLE_FLAG 0x40
  • LL_ZERO_CODE_FLAG 0x80
• Bytes 0, (4 least significant bits) to byte 3: (for a total of 28 bit) Packet ID, assigned by circuit
• Everything beyond this is potentially zerocoded for compression
• Bytes n thru n+(frequency size)
  • 1/2/4 byte ID of the message the packet contains
• Bytes n thru n+(data length)
  • Body of packet, possibly zero coded.
• Bytes n+(data length) thru acks
  • Rest of packet is fill with as many acks as will fit from reliable messages