SSL which require the exchange of numerous pieces of data between web server and web client. Although these pieces of data are small, the multiple round-trips involved in the handshake produce long delays compared to other forms of Internet connectivity, as documented by Stephen T. Cobb in a 2011 report published by the Rural Mobile and Broadband Alliance. This annoyance extends to entering and editing data using some Software as a Service or SaaS applications as well as in other forms of online work. Functions like live interactive access to a distant computer—such as virtual private networks can be affected by the high latency. Many TCP protocols were not designed to work in high-latency environments. Medium and Low Earth Orbits Medium Earth orbit (MEO) and low Earth orbit (LEO) satellite constellations do not have such long delays, as the satellites are closer to the ground. For example: The current LEO constellations of Globalstar and Iridium satellites have delays of less than 40 ms round trip, but their throughput is less than broadband at 64 kbit/s per channel. The Globalstar constellation orbits 1,420 km above the Earth and Iridium orbits at 670 km altitude. The O3b constellation orbits at 8,062 km, with RTT latency of approximately 125 ms. The network is also designed for much higher throughput with links well in excess of 1 Gbit/s (Gigabits per second). The forthcoming O3b mPOWER constellation shares the same orbit and will deliver from 50Mbps to multiple gigabits per second to a single user. The Starlink satellites orbit at 550 km altitude, with an average RTT latency of 45 ms in 2021. Unlike geostationary satellites, LEO and MEO satellites do not stay in a fixed position in the sky and from a lower altitude they can "see" a smaller area of the Earth, and so continuous widespread access requires a constellation of many satellites (low-Earth orbits needing more satellites than medium-Earth orbits) with complex constellation management to switch data transfer between satellites and keep the connection to a customer, and tracking by the ground stations. MEO satellites require higher power transmissions than LEO to achieve the same signal strength at the ground station but their higher altitude also provides less orbital overcrowding, and their slower orbit speed reduces both Doppler shift and the size and complexity of the constellation required. Tracking of the moving satellites is usually undertaken in one of three ways, using: