Tuesday, August 3, 2010
HSMM Mesh Network in Texas
In Collin County Texas a groups of hams have been making good use of HSMM technologies to update their Amateur Radio Communications Health-care Emergency Services (ARCHES). This was traditionally setup of two meter/ 70cm voice and packet radios at 9 Austin, Texas area hospitals.
The setup provides key patient data to the City of Austin Emergency Operations Center, during significant incidents, even if normal communications are unavailable. It's highly successful. During every activation, patient data and other traffic passed more quickly and accurately than all other techniques tested during the activations.
The ARCHES program has been so successful, we have been asked to expand the system to ~ 40 additional area hospitals and clinics in central Texas.
Due to the existing significant number of packet collisions using traditional packet radio with just 9 nodes, they are migrating to HSMM.
With 40 or more packet stations in the area, passing packet data could slow to a crawl due to packet collisions.
The stations could only transfer data at 1200 baud, at best. Attempts at using 9600 baud showed that common radios do not pass 9600 baud data well. They distort the data so badly, that many resends are needed to get data through.The effective data rate seldom exceeds 1200 baud.
The HSMM proof of concept was demonstrated least year by AD5OO, NG5V, and KD5MFW who achieved a 10 mile point to point link across downtown Austin, Texas using only 35mw.
The Austin HSMM SIG has incorporated Optimum Link State Routing (OLSR) into custom firmware to provide automatic linking of radios that will be placed on Water Towers throughout Collin County Texas.
For more info see: http://hsmm-mesh.org