The typical situation for this part of the investigation would be the use of Iridium or Globalstar satellite phones handsets connected to a laptop computer for email access and simple data downloads. Often these applications make use of an http- based Internet browser. Since there is no simple methodology to easily compare in a quantitative sense the browsing of web pages on the two satellite telephone systems there are problems posed. Several issues such as lost packets, busy servers, web page architecture, spooking and caching make it difficult to set up an analysis such that any potential problems can be isolated to the satellite system end of the network .It is difficult to make a fair quantitative assessment if it is unsure where the delays are introduced.
The data service part of the experiment was divided into two segments for this reason. The satellite phones were tested using file transfer protocol downloads from a server located on a high-speed connection to the Internet in order to enable quantitative measures. Two files were chosen and multiple downloads were made in order to determine the actual data rates. The second part of the research was an assessment of web browsing on both systems.
Each file was downloaded 80 times which translates to more than 20 MB downloads over the combined systems. This was done equally over the packet and dial-up modes offered by each service provider. Packet mode is where the Iridium or Globalstar satellite phones provide access to the Internet through their respective gateways and dial-up mode is where an independent Internet service provider is used to provide access.
Iridium employs a proprietary data compression technology to improve its data rates when using its packet and this makes the potential compressibility of the files important.
“This information was referenced from an evaluation made by Satellite Communications Group of Frost and Sullivan”
