HSMM

What is HSMM?
HSMM is the acronym for High Speed Multi Media. Intranet / Internet + HAM = Hintranet / Hinternet High Speed Multi Media is Voice, Video and Data. HSMM is defined as data streams =>128k over RF in amateur radio bands above =>70cm.  Most of the HSMM users operate using Off The Shelf (OTS) Wi-Fi 802.11 equipment. OTS equipment uses the Spread Spectrum mode divided into 11 channels in the frequency range of 2401-2473 MHz with channel center frequencies at 1)2412, 2)2417, 3)2422, 4)2427, 5)2432, 6)2437, 7)2442, 8)2447, 9)2452, 10)2457 and 11)2462. 802.11 uses a +/- 11 MHz each side of the center frequency for a 22 MHz bandwidth. Channels 1-6 fall within the 13cm amateur band. Amateur Radio Operators are the primary users in the first six channels of 2.4gig WiFi. As a Licensed service, we can modify Off The Shelf (OTS) 802.11 equipment within the FCC Part 97 rules.
A more detailed description is located at Wikipedia, ARRL

Why HSMM?
HSMM provides Amateur Radio Operators with;
Wide Band Communications.
Mobile or fixed location.
Internet speed: 5-54 Mb/s Voice, Video and Data, Instant Messaging, E-Mail, WEB services.
Real time high resolution Voice, Video.
Point to Point or Conference VOIP phone systems.
Large file, Short delivery time, file / data transfer.
File system to file system connection, Peer to Peer.
None proprietary low cost Off The Shelf (OTS) equipment.
With or without internet access.

HSMM Security!
Part 97 says that communication is not to be obscured. Recent developments indicate that securing HSMM networks with encryption schemes are not to obscure the communications but to secure the communications from unauthorized users. The same as securing our radios from unlicensed users. As long as we publicly announce (on a WEB Site) the encryption scheme used (not the encryption key) We are still legal under part 97. However we should make the key available to any licensed HAM in our vicinity. Other methods of securing are MAC address restrictions, IP address restrictions and replacing the RF crystal shifting the frequency so that it can not be seen by non-licensed (part 15) devices. Antenna polarization is another possable method of security. Most part 15 Wi-Fi units use vertical polarization, So HSMM uses horizontal polarization. Transverters can be used to move the output band to another HAM band. Each HAM operating in an HSMM network must have installed an up to date and operational firewall, virus protection and popup protection on their computer.


What hardware is used for HSMM?
Any OTS Wi-Fi Router with removable antennas and which will support DD-WRT software or other open source firmware may be used for HSMM. My personal preference is the Linksys WRT54G-TM (TM = T-Mobile) using DD-WRT software. However any Linksys WRT54G versions 1 through version 4, any Linksys WRT54GS versions 1 through version 4 and any Linksys WRT54GL unit may be used for HSMM and HSMM-Mesh. These units can be purchased on eBay for between $17.00 and $100.00. For HSMM-Mesh software I use mesh software from http://hsmm-mesh.org/


What is DD-WRT?
"DD-WRT is a Linux based alternative Open Source firmware suitable for a great variety of WLAN routers and embedded systems. The main emphasis lies on providing the easiest possible handling while at the same time supporting a great number of functionalities within the framework of the respective hardware platform used." Found at dd-wrt.com. Max of 50' of coax cable. 2.4 GHz high gain antenna purchased or home brew. Depending on the application an Omni directional or dish antenna. Minus the mast or tower HSMM can be accomplished for less than $100.00. To minimize RF losses in the transmission line a weather proof housing can be used to put the Wi-Fi unit at the antenna. The savings on the transmission line will be offset by the cost of the outdoor housing. Power Over Ethernet (POE) may be used to power the outdoor Wi-Fi unit as well as battery and solar panel.

HSMM Links
N5OOM's HSMM Projects
High Speed Multi-Media Using Part 15 Wireless Ethernet Devices
Using IEEE 802.11b Operating Under Part 97 of the FCC Rules
Search for HSMM hardware at eBay
dd-wrt.com
dd-wrt.com/wiki
Digital Amateur Radio Project Association
HSMM INFO
HSMM-Mesh dot ORG

HSMM PDF Files
QST April 2003
QEX Nov/Dec 2004
QST July 2005
HSMM in Albuquerque

MS PowerPoint Files (Must have MS PowerPoint installed)
Introduction to HSMM
Another Introduction to HSMM
KC0TGY Bill Wallace
N5OOM John Beadles
HSMM for Emcomm
Introduction to Linksys WRT54G
Using 802.11x gear in HSMM