Satellite’s Role in Broadband Internet access

Introduction

The Internet is changing the way we work, live, play, and learn. In just a few years, the Internet has gained worldwide attention as individuals and businesses tap its tremendous potential to quickly access all kinds of information, communicate with friends and associates, discuss ideas, and conduct business transactions. Web technology makes it easy for anyone to "get online" with minimal training. Electronic commerce is gaining momentum as companies leverage the Web to reach new markets, build sales, and improve customer satisfaction. Clearly, the Internet has changed our business-to- business and business-to-consumer paradigms. 

Market and Technologies

The battlefield for providers and manufacturers is the last mile access to the subscriber whether it is a business or a consumer. Many research studies and common sense show an immense worldwide demand. Currently, there are more than 400 Million PCs in the world with about 50 Million added each year. Experts estimate that roughly 25% of those are connected to the Internet. An increasing number of users, residential or businesses are not satisfied with the data rates a common dial-up access via 56kbps modems are capable of. Different technologies are competing to provide a high bandwidth access. The main competitors are DSL, which is using the copper infrastructure, cable modems via the cable TV network, upcoming wireless technologies such as LMDS or MMDS, and satellite access. Each of those technologies has its drawbacks but also has its market. For example, BellAtlantic admits it may never be able to serve 40% of its lines with DSL service due to technical limitations and limitations in reach. Cable modem networks are labor intensive in installation and have limited throughput when the last coax section is oversubscribed. But what are your options, when you are too far away from the central office for a DSL service, a cable provider does not serve you and there is no line-of-sight for an LMDS technology. This is where Satellite comes in. 

Why Satellite?

Satellite can fill in pockets where other technologies can’t reach. You get global coverage in a flash. There is only one network to deal with. Quality of service is high. Satellites have a certain unique advantage. They are unequaled for broadcast applications such as the delivery of the same information to a large group of users. A majority of the Internet applications in the future will be streaming, broad- and multicast services such as playing audio or video. On the other hand, satellite communications present one major challenge with respect to the performance of Internet applications -- the communication latency between two earth stations connected by a satellite. For GEO satellite communications systems, the latency is at least 250 milliseconds on each path. This is approximately 10 times higher than a point-to-point fiber optics connection across the continental United States. The latency might not affect bulk data transfer and broadcast-type applications, but it will hurt highly interactive applications that require extensive handshaking between two sites. Unfortunately, one of the major Internet transport protocols, TCP, requires such interaction. However, there have been major developments for overcoming the TCP/IP restrictions, which lie in the limited window size, the acknowledgment procedure, the slow start mechanism and such. One of the approaches STM Wireless has taken relies on Internet gateways at the satellite network boundaries to perform special functions to speed up TCP sessions. At the gateways and the end-user-terminals, TCP/IP emulation is performed. The satellite protocol is based on STM’s well proven X Star protocol. 

Applications for broadband satellite Internet access

Web browsing

The most common use is, obviously, WWW browsing, FTP access, and also electronic mail. High end users, Telecommuters and Small Office/Home Office users desire high bandwidth access, which cannot be satisfied by common technologies. Browsing as an interactive application and greatly depends on the performance of the satellite protocol. Other factors are the hit ratio of the cache server and the Internet gateway performance.
Information dissemination and broad-/mulitcast 
Satellite networks are better media to deliver bulk data, anywhere and anytime. Some illustrative examples include maps and situation awareness data, stock market and financial numbers, battlefield information, and medical data. Data broadcast, such as Webcasting, network news, and TV programs can be very expensive for point-to-point networks, but is ideally suited to broadcast satellites. Therefore, GEO satellites are far more suitable for these applications than is the traditional terrestrial network. 
Videoconferencing 
Video conferencing applications use data compression to allow two-way multi-user video conferencing connections to work over limited bandwidth channels. The PSTN infrastructure of today limits the video conferencing to one-on one, point-to-point sessions. Networks with downstream bandwidth rates as the Satellite based networks can provide the required capabilities for multi user simultaneous sessions where the downstream data combines several sites participating in the conference.
Corporate Applications
A major application for businesses is the extension of their Intranet or corporate network to all of their subsidiaries. With satellite, all subsidiaries in the spot beam of the satellite have instant access to the database at their headquarters.
Some typical examples are
•	News agencies for distribution of high resolution images, 
•	Travel agent information with up-to-date availability of rooms hotels or other facilities, 
•	Real estate agencies- with up-to-date information including video clips, 
•	Remote shopping- services including high definition images and video clips of the offered goods, 
•	Digital distribution of CDs and video to agencies for immediate launch, promotion campaigns and production 
•	Administration Data Base - Schools, universities, hospitals, ...
•	Banks – access to the customer financial data
•	Hotels – hotels in remote locations offering internet access in their hotel rooms

Distance Learning

Access to remote site containing educational oriented data as electronic library, lectures etc. can be achieved by students anywhere in the Satellite coverage area.
The content can be transmitted via the high-speed satellite channel either individually to each student or simultaneously to sub groups on a multicast like system

Internet Service Providers

ISP’s are companies that provide a range of IP based services including Internet access and related connectivity, web hosting, data warehousing and targeted information services. ISP’s can effectively use satellite communication to provide fast Internet access to subscribers or businesses, which are out of reach of DSL or cable modem providers. One of the services taking advantage of the satellites broadcast nature is Webcasting, where Video or Audio signals such as news, interviews, or reports are broadcast over the Internet. 

Local caching or mirroring is a means of improving the response times for Internet using when accessing the web. The most commonly accessed Internet pages are locally stored in huge servers. VSAT technology can be used to feed and update these local servers with the current web contents and thus improve the performance of the ISP.

Conclusion

STM has moved from being a major player in the rural telephony arena in developing countries, to providing products for broadband Internet access with SpaceWeb Broadband. STM’s broadband portfolio targets the above-described applications with a mix of different products. 

SpaceWeb Online – always only, targeting the small and medium sized businesses providing LAN interfaces to the customer
SpaceWeb PC and Dial-up – both are dial-up configurations serving the needs of SOHO’s
SpaceWeb ISP – the high end configuration for ISP’s or Enterprises

All products fit seamlessly in the telephony products. SpaceWeb Broadband is a DVB based technology with a unique TCP/IP acceleration over satellite providing the best possible performance for the lowest price possible for all applications.

Contact information:
 
Bernd Steinebrunner
VP Product Management and Sales Engineering
STM Wireless, Inc.
Bsteinebrunner@stmi.com
Phone +1 949 753 7864