*** Comparison of Satellite Telephones *** Subject: Re: SATPHONES Date: Fri, 02 May 1997 11:15:31 -0700 From: David Pottier To: sar-l@islandnet.com CC: alexander@ccinet.ab.ca At 12:42 30/04/97 -0700, you wrote: >>A few comments about two way communication. Obviously, it is great to be >A smaller version of this type of satellite phone is now availble. I was >looking at one this week, it is about a 1/4 of the size (and weight) of >the brief case ones and more advanced. Quite amazing! Last year our team used the Magellan microCOMM-M sat phones. These are way more practical for SAR work than the brief case terminals and a great deal cheaper both for their initial cost and per minute operating costs (very important). The weight is only 5 pounds and the size is a bit smaller than a notebook computer. However, we found some drawbacks in the technology. Those drawbacks were the send-receive-send limitations of the InMarSat-M system and the 2400 baud rate for data transmission and lack of secure communications (encryption) and the power supply - a heavy 12 volt motorcycle type battery. Although the newer models use much smaller batteries and take much less than 65 watts of power to transmit a signal. Our Magellan unit was about $7500 US compaired to the $17-22,000 US cost for a briefcase unit. I have heard that the newer units are down to about $3500 - $4000 US. We have migrated to a more practical and complete system and are recommending that all SAR teams consider the same type of equipment when they upgrade. Our choice was the InMarSat-B with voice and data encryption. These systems allow high speed fax and data as well as voice plus the added feature of video. These systems are also available for purchase from our team. In the field, the rescue teams use an Enhanced Digital Access Communications System (EDACS) with a series of collectors and trunk relays. Because this is a digital system voice and data encryption is easy to implement. The trunk relays feed it all back to the main InMarSat-B unit and the field command center. Encryted field video transmissions arrive and leave via a similar route. The entire system is digital and secure. Any or all of this information can then be relayed via the InMarSat-B unit to anyplace on the planet and received by another unit with matching encryption logarithms. The system is unaffected by local telco conditions and unaffected by the use of cell phones. For our purposes we use three units - two in the field (one as a spare) and one at our base in Penhold, Alberta. The HQ team can receive any data they require from the on-scene teams. HQ can monitor all field team voice traffic or disaster site video and all types of collected data, from local weather to air quality, in the case of an oil well fire response. From our Penhold HQ we can relay current Doppler Satellite imagery to the on-scene units for integration with their GPS and GIS systems. This allows field units a `bird's eye' view of the disaster area and the most seriously affected areas can be dealt with. The use of both digital TV cameras and digital still cameras means that images can be loaded directly into the system, compressed and relayed to HQ for evaluation and study. The system means that more than one disaster can be monitored and managed by one center. Medical, engineering, scientific or rescue expertise, not able to be in the field, can have direct input to the field teams. Other speciality teams and areas of expertise, with similar equipment, can monitor the scene and provide various types of support from logistics to technical, etc. Regards, David Pottier dpottier@freenet.victoria.bc.ca http://www.amerrescue.org President & CEO The Environmental Emergency Response System of Canada, Inc. - TEERS-Canada Voice/Fax: 250-480-0254 International Base and Rapid Deployment Training Center at Harvest Park College - Penhold, Alberta College - Voice 403-886-5116 Fax 403-886-5003 -----------------------------