Satellite VoIP
In remote areas with no reliable wired telephone services, deploying a voice over internet protocol system over satellite may be the best voice option. This can be problematic, however, mainly because of satellite latency:
Latency is the term that describes the time it takes to get a packet to its destination. It is usually expressed in milliseconds, or ms. Since the satellites are located 23,000 miles above the equator, and satellite signals travel at the speed of light, this journey takes approximately 540 ms. You then add on the latency of the various Internet hops and servers plus the VoIP provider’s network to end with a total latency in the range of 650 ms to 700ms or more depending on the state of the Internet itself. Another contributing factor could be the quality of your satellite signal which may cause packets to be resent. This latency is heard as a delay between the sender and the receiving ear. Users of VoIP over satellite need to learn how to communicate with this inherent latency much like the older press-to-talk radio phones. Further, the delay requires the users to be patient and refrain from interrupting the caller.
This excerpt comes from an informative white paper produced by Galaxy Broadband (below).
The recently released, DTECH WHISPER V0IP System hopes to solve some of these latency issues:
The integration of the WHISPER system with the iDirect line of satellite hubs and remotes can provide end users with up to a 600 percent increase in V0IP call capacity over a single remote iDirect satellite link. The system can also reduce the amount of bandwidth required to support standard V0IP traffic by more than 30 percent.
With its reliance on large numbers of small, delay sensitive packets, V0IP traffic can quickly stress the resources of a remote satellite link. The WHISPER V0IP System, based on DTECH’s small-footprint, high-performance integrated hardware platform, is powered by VX Software from Network Equipment Technologies to deliver greater network efficiency through packet consolidation, header compression, and call consolidation.
This feature set reduces the number of packets and overhead required to support a V0IP call. A 1.5 Mbps iDirect satellite link can support more than 150 simultaneous V0IP calls, while a 3 Mbps remote link can support more than 250 simultaneous V0IP calls. The combined increase in calls per packet with the reduced bandwidth required allows network operators to utilize the same space segment they currently lease to provide a more robust voice network and greater capacity for data traffic.
