Northern Sky Research

The Move to Full SCPC-TDMA Convergence

Oct 26th, 2012 by Carlos Placido   More from this Analyst | Profile

Shaped by the vision of an all-IP future, satellite markets served by TDMA and SCPC solutions have blurred over the past several years. Products and feature enhancements introduced by manufacturers at either camp have consistently reinforced this notion that, despite conceptually different ways of accessing satellite spectrum, there is increasing overlap among the market segments that TDMA and SCPC equipment vendors target.

One clear example of SCPC-TDMA convergence can be perceived in iDirect´s recent release of performance measurements on the Evolution X7 Remote. On October, 17th iDirect announced reaching 100 Mbps of aggregate IP throughput using the new X7 Evolution modem, operating with either TDMA or SCPC return access. Triple digits in Mbps of aggregate throughput flowing through a single site has, until recently, been only possible using SCPC modems.

For years, SCPC technology has been associated with dedicated point-to-point links and TDMA with shared multipoint applications. Peak data rates as well as network topologies and end-to-end latency requirements were also considered aspects defining which technology to use. However, these associations are gradually disappearing. The iDirect announcement follows a number of product launches and moves by other key players, reinforcing this notion of convergence. Sample developments include:

  • Gilat´s launch of the SkyEdge II Accent Dual Waveform VSAT, featuring a dual SCPC/TDMA return
  • Comtech´s development of the Advanced VSAT system, combining outbound DVB-S2 ACM with SCPC returns to better serve multipoint networks
  • Newtec´s diversification from broadcast and multipoint products towards TDMA and SCPC
  • Romantis´ release of a satellite router supporting various modes of operation and topologies including SCPC, TDM/SCPC, TDMA/TDMA and partial / full mesh

Beside the benefits of operating in both TDMA and SCPC modes at high speeds, one key aspect that NSR envisions will become the norm (when technology vendors introduce high-performing edge systems) is the ability to gradually incorporate software-definable enhancements that augment a platform´s future value. It is expected that iDirect will utilize the X7 Remote as a springboard to port process-intensive edge enhancements in future releases of its iDX management software.

Such an ability to simultaneously provide flexibility and performance is key in high data rate applications. Towards high-speed links, the CAPEX/OPEX value proposition shifts the attention to OPEX-saving considerations.  With most systems closely approaching the limits of efficiencies at the transport layer, future efficiencies will need to come from the use of sophisticated application-aware compression and bandwidth optimization.

The introduction of a high-speed modem by iDirect could also position the company as a flexible alternative to SCPC modems for high-speed links over specific high-throughput satellite (HTS) networks, such as O3b. Given the low-OPEX, high(er)-CAPEX characteristics of O3b (relative to traditional FSS) their value proposition will tend to make economic sense towards high data rates. For a long time, there have been questions of whether O3b would embrace SCPC solutions, TDMA or both. The iDirect X7 lowers the perceived risk by offering both TDMA and SCPC returns with high aggregate IP throughputs.

Bottom Line

Just like other aspects of the industry, satellite ground networks are being reshaped by the globalization of high-throughput satellites and technology evolution, enabling higher processing power at the network edge. Looking forward, NSR envisions interesting innovations like the X7 that will equip service providers and operators with new levels of flexibility, speed and operational enhancements.