End to End

The challenges of using satellites in end-to-end communications links: GEO satellite networks have the potential to provide the end user the ability to receive broadcast and multicast in greater amounts of information at higher rate of speed providing global connectivity anywhere within the footprint of the satellite. On the other hand there are several challenges that are presented when utilizing satellite networks. These challenges are seen by the end user in several different formats; the most common one being in Internet applications.

The latency experienced by the end user due to the communication between two earth stations can be significant and often annoying. A tremendous amount of military and government organizations utilize and rely on satellite communications, when that path fails due to blocked areas, lack of available bandwidth or atmospheric interference then this becomes a serious situation and another reason why redundancy and a secondary and tertiary plan is always needed.

Point to point fiber optic connections can provide a solid backup plan if availability is an option. The latency may not affect bulk data transfer and broadcast type applications, but those applications requiring extensive “handshaking” between two sites will be undoubtedly affected. TCP which is one of the Internets major protocols requires such interaction. Satellites that can provide the end user with global and broadband communications capacity are also an option but also come with challenges of its own.

LEO(low earth orbit) and MEO (medium earth orbit) each are a viable source that provide latency times comparable to that of a terrestrial fiber optics; however because neither can remain in a constant fixed position relative of that of the earth, a constellation of several satellites is required to maintain comprehensive coverage. In this case network management becomes increasingly more complicated due to handoff to another satellite, tracking problems and proper routing plans. The advantage of a simple topology is no longer a factor and lost is single-source broadcast/multicast capability and brings you back to ground zero.