Some idea for IPv6 addressing for radio-amateur nodes

Note: This presumes use of WLAN hardware, translated/amplified to ham frequencies at and above 2.4 GHz

Note also: changing the RF modulation away from Bell-202-over-NBFM to something better (about anything!) and having some sort of FEC on the signal can result in a way better link processing. Japanese D-STAR uses GMSK and some sort of a Turbo-code.

For example with SDR-type hardware it is trivialish to implement moderate speed e.g. GMSK signal with convolution coding. (BT=0.3: frequency occupation delta-f is circa 2* encoded bitrate; 3/4 convolution codec means that 75% of channel bits are user data. ==> 25 kHz channel can handle up to 9375 bits/sec of user payload data. Without any convolution coding max payload bitrate is 12.5 kbps)

Given that:

AX.25 is recommened format for packet radio frames
RFC 2460 Internet Protocol, Version 6 (IPv6) Specification. S. Deering, R. Hinden. December 1998. (Format: TXT=85490 bytes) (Obsoletes RFC1883) (Status: DRAFT STANDARD)
RFC 2461 Neighbor Discovery for IP Version 6 (IPv6). T. Narten, E. Nordmark, W. Simpson. December 1998. (Format: TXT=222516 bytes) (Obsoletes RFC1970) (Status: DRAFT STANDARD)
RFC 2462 IPv6 Stateless Address Autoconfiguration. S. Thomson, T. Narten. December 1998. (Format: TXT=61210 bytes) (Obsoletes RFC1971) (Status: DRAFT STANDARD)
RFC 2463 Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification. A. Conta, S. Deering. December 1998. (Format: TXT=34190 bytes) (Obsoletes RFC1885) (Status: DRAFT STANDARD)
RFC 2464 Transmission of IPv6 Packets over Ethernet Networks. M. Crawford. December 1998. (Format: TXT=12725 bytes) (Obsoletes RFC1972) Status: PROPOSED STANDARD)
RFC 2472 IP Version 6 over PPP. D. Haskin, E. Allen. December 1998. (Format: TXT=29696 bytes) (Obsoletes RFC2023) (Status: PROPOSED STANDARD)
MOBILE IPv6 !

We see that there is massive scale packet growth in horizon, when AX.25 header puts minimum of 16 byte address header for UI-field encapsulated IP frame, and IPv6 addresses glob up 16 bytes for each sender, and destination addresses.

Maximum size of AX.25 frame

Use of COTS WLAN hardware to run essentially ethernet over radiowaves, we can have:

card-specific MAC addresses (not identifying stations!)
storing station owner callsign into IPv6 address "network local" subfield.

  |--------------------------------|------------------------------------|
  | NETWORK                        |  LOCAL                             |
  |2001:XXXX:XXXX:XXXX:XXXX        | 0x00,'O','H','2','N','X','X',0x00  |
  |---------------------------------------------------------------------|

For local part:

Local address byte 0 is defined constant zero, and reserved for future use.
Local address bytes 1 thru 7 encode (in uppercase ASCII) station callsign.
- Alternatively encoding the text in 6 bits per character (see RTTY), useful with lengthening of the callsigns.. - stores 8 characters easily in space of 6 (mid) bytes.
- Leave last byte free for SSID values..
Encoding AX.25 SSID value into 8th bit of callsign (local address bytes 1 thru 4) allows up to 16 separate values (like AX.25 does now.)
High bits of local address bytes 5 thru 7 (3 bits total) are reserved for future use.

In classical packet-radio environments dropping of digipeating (dropping 104-216 bits of address) is supported as:

A1 - Link address byte, any ODD value, e.g. default: 0x01
Control - 'UI' = 0x03
PID - ARPA Internet Protocol = 0xCC
... IPv6 frame with address encoding station callsign ...

The IPv6 address encoding method can not handle AX.25 digipeater routing things. Similar things can be accomplished with IPv6 "routing header" along with the TTL (max hop count) field.

Things like AX.25 digipeat of APRS frames to WIDE* targets can be done simply with destination address having suitable target, plus TTL (max hop count) limiting on how many redistributions are allowed.

Area-destined messages could be addressed by choosing a set of multicast addresses that are directed to those areas.

The target address could be encoded to contain area limits in such distributions.

For COTS WLAN hardware links, standard RFC 2464 format shall be used.