A Resilient Digital Emergency Communications Network for Maine

Steve Hansen Richard Bates Donnie Dauphin KB1TCE WD1O WD1F

April 23, 2019 Acknowledgements

• Roger Pience N1XP • Jimmy White KC1ETT • Pete Thuotte N1ZRL • Our EMA Directors • And many more Outline • Introduction • How a packet network works – Node hardware and software – Features for resilience – Performance • How you can use the network – Client hardware and software – ElExample from recent MMltiulti‐CtCounty SET – Extending coverage with . HF radio . Win lin k RdiRadio‐EilEmail StSystem . Digital Traffic Network • Demonstration • Discussion Completing the Picture

At last year’s conference we covered the Knox County Neighborhood HamWatch program. This year we are covering multi‐county, statewide, national and international emergency communications using Amateur Radio. Simplified Packet Network

N1ZRL KB1TCE

• N1ZRL connects to his home BBS to send a message to KB1TCE. • The system knows KB1TCE as KB1TCE@EOC.#KX.ME.USA.NA • Message is ffddorwarded via one or more nodes. If a node is not available, the network will try to find an alternate path. • Nodes may have multiple functions e.g. node only, internet gateway for Winlink, BBS. Network as of March 2019

Windham and Libby Hill (Gardiner) are in progress.

MEMA can connect via Lenfest Mtn. or Aborn Hill.

Entry to the Canadian Maritime Packet Network (MARCAN) via New Brunswick and Nova Scotia.

HF access is backup and also provides statewide access.

The website http://nodemap.g8bpq.net:81/ automatically maintains a world‐wide map of internet‐connected BPQ network nodes Outline • Introduction • How a packet network works – Node hardware and software – Features for resilience – PfPerformance • How you can use the network – Client hardware and software – Example from recent Multi‐County SET – Extending coverage with . HF radio . Winlink Radio‐Email System . Digital Traffic Network • Demonstration • Discussion Packet Node Hardware using Raspberry Pi

• Without Internet access, the real‐time clock enables secure over‐the‐ air administration using BPQAuth.EXE

• Backup battery eliminates problems of SD card corruption due to power outages Packet Node Software

BBS, node and gateway software developed by John Wiseman G8BPQ. Supports many HF and VHF/UHF modes. Versions are available for Windows (BPQ32), Linux (LinBPQ) and the Raspberry Pi (PiLinBPQ). Example of Console for node KX1EMA‐15 running PiLinBPQ

current version

node configuration file

UHF and VHF ports initialised

mail configuration file Features that give Resiliency

• Moderate‐persistence CSMA/CR ‐ nodes that are polite and listen

• Error‐detection in AX.25 ‐ corrupted frames are re‐transmitted

• Automatic routing with NET/ROM ‐ adjust for changing propagation, node failures, etc Reference Model for Open Systems Interconnection (OSI)

• Some applications, like apps, do not use all the upper layers Packet Radio Layers

• AX.25 – derived from X.25, a 1970’s telecom’ protocol (users included ATM)

• HDLC ‐ High Level Data Link Control

• CSMA/CR ‐ Carrier sense multiple access with collision recovery

• 1200 b/s uses old Bell 202 tones –1 = 1200 Hz & 0 = 2200 Hz Moderate –persistence CSMA/CR

ElExample with radios A, B and C sending messages Conceptual CSMA/CR Performance with Persistence ALOHA: just send 1.0 p = 0.1 0.9 p = 1: send if idle 080.8 0.7 p < 1: send if idle p = 0.5 0.6 and x < p ghput

uu 005.5 0.4 p = 1 Thro 0.3 Higher throughput is achieved 020.2 with moderate‐persistence, p ALOHA 0.1 (politeness) 0 Offere d Tra ffic LdLoad Error Detection in AX.25

Flag Addresses & Control PID Information FCS Flag AX.25 Frame Structure • Flag ‐ 1 byte delimiter at beginning and end of each frame • Addresses (Sender and Receiver) & Control –typically 16 bytes • PID –Protocol Identifier, e.g. “no layer 3”, NET/ROM, TCP/IP • Information –up to N bytes in this packet • FCS –Frame Check Sequence, a 2 byte Cyclic Redundancy Check (CRC) The CRC is computed using at Transmitter and inserted into the frame At the Receiver the CRC is again computed and compared to what was sent If the two CRC numbers differ, a request is sent back to the Transmitter ‐ resend the frame 2 byte CRC can detect errors in up to 16 contiguous bits & others distributed across frame Principles of CRC for Error Detection • At the Transmitter the AX.25 frame is “divided by” a number

Data Input using CRC‐16‐CCITT standard generator polynomial x16+x12+x5+1 • The Tx‐remainder is inserted into the frame as the FCS • At the Receiver the received data is “divided by” the same number • The Rx‐remainder is compared to the received FCS • If they differ, the Receiver requests the frame resent An Illustrative Analog with Decimal Numbers • Start with 30‐digit number 9876543210987654321098765432109876543210 • Diidivide by the number 19 to get a remaidinder 1 and transmit this as the FCS • Receiver gets 9776543211987654321099765432109876543220 • Divide by 19 to get a remainder 14 • Conclusion ‐ there are errors in the frame so request resend note: calculation done with large number calculator https://www.calculator.net/big‐number‐calculator.html Automatic Routing with NET/ROM

Flag Addresses & Control PID NET/ROM Information CS Flag AX.25 Frame Structure with NET/ROM • NET/ROM is used for messages between nodes • NET/ROM is layer 3 –the Network Layer protocol –to accomplish routing • NET/ROM layer reduces the Information packet size by 20 bytes • Each node: • periodically announces its existence (FCC ‐ every 10 minutes) • creates a Neighbor list – nodes it can “hear” directly • creates a Destination list –nodes it has calculated it can hop to • periodically announces its Destination list (typically every hour) • The Destination list can have up to 3 routes to each node Neighbor & Destination Lists B

A D

C Nodes A, B, C & D

Example: Destination Details from Node at St. George, ME to Yarmouth, NS N VE1YAR-1 Query: routes to node VE1YAR at Yarmouth KNXSTG:WD1O-15} Routes to: from node WD1O‐15 at St. George? #yar:VE1YAR-1 Response: routes to node VE1YAR‐1 198 5 4 KS1R-15 ‐ via node KS1R‐15 at Phippsburg ‐ quality 198 174 5 4 KX1EMA -15 ‐ via node KX1EMA‐15 at Rockland – quality 174 174 5 3 WD1O-5 ‐ via node WD1O‐5 at Lenfest – quality 174 Data File Used for Network Testing

50 names, phlhysical and email addresses, and phone numbers

~4 kBytes .CSV file ~ 2.5 kBytes compressed How Good is 1200 b/s Packet Radio?

–delay waiting for idle channel

– transmitter turn‐on delay Outline • Introduction • How a packet network works – Node hardware and software – Features for resilience – Performance • How you can use the network – Client hardware and software – Example from recent Multi‐County SET – Extending coverage with . HF radio . Winlink Radio‐Email System . Digital Traffic Network • Demonstration • Discussion User Configuration

• Windows computer to run Winlink Express. • A hardware packet TNC or a sound card interface used with appropriate packet software. • VHF or UHF radio as needed. User Packet Software

• Many options are available. We use Winlink Express bdbased on bbdthreadth of use and ffteatures tha t support emergency communications. • Winlink Express: – Client software developed by the Winlink Development Team. – May be used for packet networks or with the Winlink radio‐ email system. – Functions with a broad set of ARQ modes for VHF/UHF packet and HF. – By default, uses Open B2F compression to minimize message size. – Accommodates text and binary file attachments. Winlink Express Main & Session Screens

Main screen is set up like an email client. Session screen sets the mode and manages the connection. Example from Multi‐County SET January 26, 2019 Lenfest WD1O‐5 Rockland KX1EMA‐15 Rockland Whitefield EMA N1REX‐15 St. George Phipps burg WD1O‐15 KS1R‐15 Wiscasset EMA • Packet messages exchanged between the EMA Directors of Lincoln & Knox County • Sent by K1LX at EMA in Wiscasset, connecting to node KS1R‐15 in Phippsburg • Message automatically routed via node WD1O‐5 at Lenfest to node KX1EMA‐15 in RkldRockland (there was a alterna tive path via WD1O‐15 in St. GG)eorge) • Message received at EMA in Rockland by KX1EMA Adding HF to the Network Hardware Configurations

• Same software as for packet. • Compatible HF ARQ sound card modes include Winmor, ARDOP & VARA • Pactor (HF): Proprietary hardware (=$$$) but highest HF performance. HF for Extended Coverage

• VHF/UHF pack et is basi call y line of ssgight aadnd requir es an infrastructure of nodes. • The network can be expanded by adding a limited number of HF ports. These can be accessed state (and region) wide using the same software and protocols. • Shou ld there be a filfailure of the VHF/UHF nodes, HF can help to fill the gap. • However, HF modes are slower than packet and any station can only accept one connection at a time. Packet Network with HF Ports Adding Winlink to the System What is Winlink?

Winlink is a worldwide radio email service that uses radio pathways where the internet is not present. It is also capable of operating completely without the internet‐‐automatically‐‐using smart‐network radio relays.

Winlink had its origins with the sailing community with email, position reporting and weather information. It now has a substantially broader role supporting emergency and disaster relief communications.

Winlink also supports non‐ham governmental communications, one notable example being the SHARES (SHAred RESources High Frequency Radio Program) that is administered by DHS.

The system is built, operated and administered entirely by licensed volunteers. Support for the system is provided by the Amateur Radio SftSafety FdtiFoundation, Inc., a US 501(c )(3) non‐profit, public‐bfitbenefit entity. Hardware Configurations for Winlink

Same as before except that Winlink offers telnet as an option. Use if bandwidth is limited and the internet is available locally. Winlink System & Linkages

“Radio‐Only” is ppyrimarily a backup if no internet connected RMS is available. Winlink RMS Map Message Routing: Example 1

• A remote station in northern Maine and has no access to conventional communications. Fortunately the op is equipped with a portable HF digital station. • The station connects by a HF mode to the WD1O RMS in Tenants Harbor. • WD1O automatically relays the message to the CMS via the internet. • The receiiiving sttitation has no radio btbut can connect to the internet through their regular email. • The system works in the other direction. • The remote station could also access the packet BBS network by connecting to WD1O‐2. Message Routing: Example 2

The process is the same as that shown in Example 1. Station A is in an area without standard communications services. It connects by HF to a RMS outside the affected area. Station B connects to a local RMS via packet and the message is retrieved. Another Linkage: The Digital Traffic Network (DTN) The RRI Digital Traffic Network • Grew out of NTS‐Digital. • For the transfer of radiogram format messages. • Complements and interoperates with the manual traffic (cw, ssb) NTS and RRI nets. • Routing is by postal code and physical address. This provides multiple options for delivery. • The network consists of two types of stations: – A number of Hubs (aka MBOs) that run BPQ and connect to each other using Pactor 3. Operation is automatic, 24/7. – A larger number of Dig ita l TTffiraffic Stati ons (DTS) using Airma il or Win lin k Express client software that connect manually to their designated Hubs. Common modes include Pactor 1‐3 and packet. (Local modes are at the discretion of the Hub Sysop.) DTS operators work with their state and local manual nets. • Hubs are currently located in the USA (including Hawaii) and Germany. Network expansion is ongoing. • Recently created a link with the Winlink System via the Winlink‐RRI Liaison program. How the Maine DTN Hub Fits In Submitting a Radiogram to KB1TCE • Winlink, packet, voice or whatever works (bring to my door if you wish). • Use correct text format or a helper tool that is compatible, i.e. Flmsg or the Winlink Express Radiogram Text Creator.

Radiogram Text Creator Normally used with Winlink to send a radiogram to a Winlink‐ RRI Lia ison, it may be used with the packet network when addressed to KB1TCE.

Substantial set of helps makes formatting easy for the novice. Message via DTN from Maine to CA

• Message arrives at Maine DTN Hub by any of a variety of methods. • Message is injected and automatically relayed via various Hubs to the Hub closest to the destination (based on postal code). • Depending upon conditions, alternate routes may be selected, as determined in the routing software. • Digital Traffic Station in the Map Showing US DTN Hubs area picks up the message Hawaii and Germany not shown. and arranges for delivery. Demonstration

Using Winlink Express

at Augusta Civic Center Lenfest WD1O‐5 email to end‐user Rockland KX1EMA‐15 RMS Winlink CMS Amazon Web Service Sending 50‐name/address data file over packet network, into the Internet via Winlink, to end‐user email Discussion

This presentation may be found in pdf format at http://kx1ema.org/documents.html Addenda

• Glossary – Packet Terminology – Packet Network Elements • Common ARQ Modes and Transfer Times • Stations in the Network General Packet Terminology • Packet Radio: A system of digital communication whereby information is broken into short bursts. The bursts ("packets") also contain addressing and error‐detection information. Originating with VHF packet networks using the AX.25 protocol, the technique is used for other systems and frequency bands • Packet Network: Several packet stations linked together to transmit data over long distances. • Store and Forward: Messages sent to intermediate stations (nodes) where they are saved and sent at a later time to the final destinations or to other intermediate stations. At each step, messages are checked for integrity (ARQ mode) before passing along • ARQ: Automatic Repeat on reQuest. An interactive error correction mode used for all message transfers between connected pairs of stations. • Hierarchical Addressing: A standard addressing scheme for directing messages throughout a packet network. Hierarchical address elements are the foundation of the digital forwarding system. Example: WD1O@STG.#KX.ME.USA.NA • TNC (Termnal Node Controller): A device that converts a computer's digital signals into audio signals for radio while providing control signals to key the radio. A TNC may be implemented in hardware or the function may be performed with software and a sound card. Packet Network Elements • Packet Digipeater: A packet‐radio station used to retransmit signals that are specifically addressed to be retransmitted by that station. It receives, stores and immediately retransmits packets. To reach a distant station, a path through one or more digipeaters must be specified. • Node: A more efficient alternatives to digipeaters. Each node periodically beacons and then learns which other nodes can be heard. Once a message enters the network, the nodes determine the best routing. An example is the NET/ROM protocol. • BBS (Bu llet in BdBoard SS)ystem): SSitations where messages are stored for retrieval. Also called an MBO (Mailbox) or Hub. • Gateway: A node or BBS that is connected to the internet. Most frequently this is for the Winlink radio‐email system. • Sysop (System Operator): The essential person who manages each node, BBS and gateway. Compensates for outages, corrects mis‐ routings and monitors traffic. Connected ARQ Modes & Transfer Times

Mode Transfer Time Packet 1200 (Direct) 2 minutes Packet 1200 (1 node) 252.5 minutes Packet 9600 (Direct) 1 minute Pactor 1 15 minutes PtPactor 2 4 miitnutes Pactor 3 30 seconds Pactor 4 15 seconds Winmor 500 10 minutes Winmor 1600 3 minutes Telnet << 1 second • The times are based on a 4kB message after compression (7.4 kB before). Data from the Winlink FAQ. Does not include connect (handshaking) time. • ARDOP can approach Pactor 2 speeds under good conditions at both ends. • VARA (3rd party) can approach Pactor 3 speeds under good conditions at both ends. • Pactor 4 is not yet Part 97 legal in the USA as the symbol rate exceeds 300 baud. Network Stations & Functions Call Sign Location Node BBS Winlink RMS HF DTN Hub

W1YCA Alfred (YC EMA) ‐4 ‐1 ‐10 No KC1ETT Wells Beach ‐4 ‐1 ‐10 Yes AB1VX Acton ‐10 No N1XP E Waterboro ‐4 ‐1 ‐10 No WS1EC Windham (CD EMA) In Progress N1ZRL Lisbon Falls ‐15 ‐2 ‐10 No WD1F Portland ‐15 ‐2No KS1R Phippsburg ‐15 ‐2No N1REX Whitefield Fire Station ‐15 ‐2 ‐10 No KX1EMA Rockland (KX EMA) ‐15 ‐2 ‐10 No WD1O Tenants Harbor ‐15 ‐2 ‐10 Yes WD1O Lenfest Mtn, Washington ‐5 ‐1No W1EMA Aborn Hill ,Knox ‐1No KB1TCE Owl’s Head Yes Yes Other Libby Hill, Gardiner (Planned Node)