Description
The relatively long propagation delay of a signal over a satellite link has always caused performance limitations and has had a negative effect on the user's Quality of Experience. This started from the early days of analog telephony to the early Internet days where throughput was limited due to the fact that the TCP protocol windows were not optimal for links of long delay and high bandwidth, such as satellite links. This led to the introduction of hardware and software solutions such as Performance Enhancement Proxies (PEPs) at satellite gateways that could mitigate the problem. However, the establishment of end-to-end secure links that is now gradually dominating Internet traffic means that these techniques are no longer effective, and as a result even a simple web page takes much longer to load over satellite, compared to any terrestrial alternative path. Increasing the satellite channel bit rate will not improve this performance. At the same time, more applications are being introduced with ever more stringent latency requirements while the terrestrial wireless world is starting to converge toward latencies of less of than 10 ms (as identified by 5G standardization discussions).
One way to deal with this issue for the satellite industry is to move to satellite constellations at lower orbits. These systems offer the value proposition of lower latency for services, taking the one-way propagation delay down from 267 ms (GEO) to 75 ms (MEO) and 21 ms (LEO). However, these systems have significant cost and risk implications, and offer latencies still much higher than the ones envisioned by fiber or 5G networks.
There is clearly a need for the satellite industry to tackle this problem head on in a unified way. The main objectives of this activity will therefore be to: Identify the impact of satellite latency (for GEO, MEO and LEO architectures) to different classes of applications including:
- Real-time communications
- Current and future Internet protocols (e.g. TCP, http, https, IPSec, SPDY)
- Mobile applications
- Extremely delay sensitive applications (e.g. online gaming, financial transactions, emergency and life-critical applications) Propose hybrid architectural solutions and protocol modification solutions that offer distinct performance improvements for these applications by trading off advantages and drawbacks.
As a minimum this shall address:
- Transparent enhancement of Internet Protocols over satellite in the presence of secure links. (Issues suchas TCP in the presence of IPSec and issues with HTTPS where the certificate exchange at the start of each conversation cannot be spoofed).
- Enhancements enabling efficient 5G Backhauling over satellite within the 3GPP standards Quantify the performance improvements of the suggested solutions using simulation Provide and support a set of recommendations that can be used by interested parties to affect the evolution of satellite friendly Internet protocols and 5G network standards.
Tender Specifics