By Peter Brown

At the Internet Protocol (IP) via satellite cafe, voice over IP (VoIP) has slipped quite quietly onto the menu. Is VoIP via satellite ready for the main course? Or is it an emerging application designed to meet the needs of scattered, niche audiences? Yes, it is real, and while it may appear to have a niche-like character, things could boil over at any moment, especially in developing markets.

One of the main things which will drive the growth of next-generation converged networks is the changing role of service providers. Today, only 28 percent of sites that are connected to data networks use managed services rather than private lines. However, when you make it a virtual private network (VPN) with VoIP, this trend reverses and you see 81 percent of sites want to use managed services. This puts service providers in a much stronger position,” says Terry White, senior director at Parsippany, NJ-based Phillips Group, and author of a new study entitled “IP Telephony Managed Services: Market Demand for Converged Network Services.”

“It is still very early in the growth curve,” he adds.

This notion that VoIP via satellite might be quickly meshed with the new terrestrial wireless platforms may seem exciting from the standpoint of providing a seamless way to launch new telecom services in a variety of markets. However, there is a wide difference of opinion about how quickly PTTs (government-run departments of post, telephone and telecommunications) are going to open their territories to VoIP with or without a wireless or cellular interface.

Will the PTTs play a major role in the rapid spread of VoIP via satellite? According to William Ingram, president and CEO of Nuera Communications Inc. in San Diego, while the rapid adoption of VoIP via satellite worldwide is “a direct thrust at the monopolistic position of foreign PTTs,” he indicates that the PTTs are changing their strategy at the same time.

“Now, the PTTs are getting into the game themselves. They see that if they offer the service and drop the price, they can pick up 80 percent or more of the new revenues. If they go ahead and build out the VoIP portion in the sky, they enable massive growth in the shortest span of time,” Ingram says.

How much VoIP over satellite traffic is out there today? That remains a mystery because it is not easy to determine how much of the IP traffic flowing through a particular gateway is IP data, and how much is VoIP.

Maryland-based Shiron Satellite Communications Inc. has tested Vocaltec and Lynks VoIP solutions on its Intersky Broadband System, which is offered through Esat and Netsat Express, according to Arnon Spitzer, Shiron’s general manager.

“Although our Intersky two-way system supports all IP applications, we really do not see many requests for VoIP, at least not now. It is not driving the market, although it is running as an application on top of the Internet and corporate Intranets,” Spitzer says.

The team at Comsat Laboratories in Bethesda, MD, is rolling out the new Linkway.IP VSAT solution, and preparing for a number of new services.

“VoIP is not driving it yet. At least this is true in the IP broadband networking arena,” says Bruce Fakhari, Comsat Laboratories’ director of satellite networking products. “Internet data is driving it, although the distinction between IP data and IP voice is becoming increasingly fuzzy.”

Jacques Couet, vice president of products and services for Bethesda, MD-based Skybridge LP, says that VoIP is very important to developing countries, and that VoIP via satellite might be viewed as a narrowband, trunking solution for Skybridge since the low delay characteristics of low-earth orbit (LEO) systems provide the desired quality of service. Skybridge will start its service in 2003 using a constellation of 80 LEO Ku-band satellites.

“Anything that is a packet will be ideal for Skybridge. We will support over-the-air broadband interfaces as well as many different classes of service. We will offer global coverage using 140 gateways,” Couet says. “We will simply provide access to service providers who then decide how to mix classes of services with the services they want to offer.”

Making Headway

Besides Comsat Laboratories, Shiron Satellite Communications, and Nuera Communications Inc., companies such as Hughes Network Systems (HNS), Startec Global Communications Corp., Interpacket Networks Inc.–just emerging from an IPO-related quiet period as this article was under way–and Memotec Communications Inc. are devoting considerable energy and making substantial headway with this application.

“There are no special considerations for the space segment. A 64 kbps circuit can roughly accommodate seven simultaneous voice circuits of 8 kbps, if the circuit is purely used for voice. However, the same circuit or channel can be used for data and voice simultaneously, and IP networks would have to be engineered to accommodate both,” says Andrew Lee, senior engineer at Intelsat Technical Labs in Washington, DC. “Various antenna sizes and space segment would also have to be considered for different traffic requirements and the frequency bands used.

“We have used COTS equipment for all our VoIP via satellite demonstrations. We are also planning to use COTS for the field trial we are planning in the near future with Kenya,” he adds.

Nuera’s ORCA (Open Reliable Communications Architecture) carrier class VoIP gateways have been embraced by Panamsat Corp., and earlier versions of Nuera gateways are used by Loral Cyberstar, which has deployed them in Europe and South America, according to Ingram, who describes Nuera’s role as providing the intelligence for voice processing, switching and call set up.

“Voice is the most favored service, and it is clearly price elastic. As far as satellite-based switched voice is concerned, you have to get it there first and make it sound good,” Ingram says. “When you compare IP switched voice service to traditional circuit switched voice service, IP offers to do it at a dramatically lower cost, roughly 10 percent of the cost of the traditional circuit switch-based solution. As a result, we expect IP voice services to achieve rapid acceptance in the satellite-based networks.

“We use the best-performing digital processor, Texas Instruments’ 1600-MIP C6X, in order to drive latency down very low to 62 ms,” Ingram adds. “This, combined with our resident DSP expertise, results in our ability to achieve a call completion ratio well over 99 percent, along with very fast translations of signaling protocols. This low latency allows IP switched voice to navigate double satellite hops with a high level of quality.”

Ingram indicates that, among other things, Nuera has provided Hughes Network Systems with IP-enabled voice code technologies.

According to Alvaro T. Gazzolo, senior vice president of the Atlantic Ocean region at Connecticut-based Panamsat Corp., most of Panamsat’s VoIP via satellite traffic is flowing as part of the Spotel offering on PAS 5 using Panamsat’s uplink facility in Homestead, FL, outside Miami. Panamsat’s Napa, CA, uplink is also being equipped to handle this traffic as well.

Panamsat taps Nuera’s F200D unit, although Gazzolo indicates that upgrades to the Nuera ORCA GX-21 are planned, and that the Nuera 7000s will be deployed soon at remote sites or nodes. Meanwhile, the F200D can support eight full E1s, or well over 16 Mbps for VoIP, along with fax and modem traffic.

“Nuera provides us with the most cost-effective and technologically advanced solution today. Their ORCA reduces delay throughout the system. We also use Cisco Systems’ routers and gateways,” Gazzolo says. “We have been operating a switch for the past three years in Homestead which accommodates SS7 protocols. Bell South interconnects through Homestead. We also have interconnects in Napa with Metromedia Fiber Network (MMFN, formerly Abovenet).

“While we use DAMA and SCPC platforms to interconnect to VoIP nodes, for our IP multicast version of VoIP, we are using SCPC only,” Gazzolo says.

Gazzolo identifies Latin America, West Africa, Eastern Europe and the Middle East as the hot growth markets for this IP-based service.

Pass The Feeds Please

Jacques Bitton, director of marketing and business development at Montreal-based Memotec Communications Inc., points out that while VoIP is not fully developed, customers are lining up already because they can see the immediate benefits in terms of reducing overall telecom costs and increasing productivity.

“This will not only enable multimedia presentations at the desktop, but it will also substantially reduce the cost of long distance phone calls. We are addressing the quality of service issue by implementing differentiated services using prioritization techniques applied at the link level,” Bitton says.

Memotec brings strong signaling support to both its VoIP and voice over frame relay (VoFR) efforts. Its lineup of access switches is being expanded, says Tony Lomas, Memotec’s product manager, to accommodate a strong market trend involving the deployment of GSM mobile phone networks with VSAT interfaces.

The ability to pass GSM data feeds across VSAT networks involves the spoofing of the GSM data protocol in order to link networks together. To take this to the next level as far as reliable and efficient internetworking is concerned, Lomas emphasizes that one has to resolve the tricky process of using the GSM voice stream as a way to transmit GSM applications data such as fax and messaging.

“You have to take it down to the bit pattern. And you cannot attempt to voice compress the data, because it corrupts the data,” Lomas says. “We have a patent application involving a spoofing process for data over GSM, and how to detect the signaling of the datastream. We reduce the bandwidth consumption, and we reduce the bandwidth constraints of SS7 as well. We have tested our implementations in single and double hop environments with impressive results,” he adds.

Beyond Proof Of Concept

According to Fawad Abbas, supervising engineer at Intelsat Technical Labs, the presence of any satellite-based latency or delay in the conventional GEO-based delivery mode for VoIP does not undermine the viability of this type of service.

“The satellite delay, at 270 ms, is well below the limit at 400 ms, the threshold which is considered to be the cut-off point for satisfactory or near toll quality voice traffic,” says Abbas.

At two meetings, in Bangkok and Philadelphia, of the European Telecommunications Standards Institute’s (ETSI) Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON) project, Intelsat conducted demonstrations of VoIP over satellite as part of Intelsat’s extensive and ongoing Internet over satellite road show.

“We have moved well beyond the proof of concept stage. We have done our homework. There are really no quality or performance issues which we have not addressed in a satisfactory manner,” says Lacine Kone, Internet senior marketing manager at Intelsat.

One of the more appealing aspects of VoIP today as far as Intelsat is concerned is the ease with which VoIP traffic can be interfaced with wireless local loop (WLL) networks. Does VoIP fit neatly into Intelsat’s broader game plan for this reason?

“Very much so. We think that in conjunction with WLL, this technology has many advantages for use, particularly to provide voice and data services for rural and under-served communities around the world,” Intelsat’s Lee says.

Comsat Laboratories’ Fakhari sees WLL in terms of microcell extension, and disaster recovery as a major focus for VoIP via satellite for broadband applications when more than four channels per site are required on average. He also thinks that in many large-scale rural telephony projects, the time frame for IP implementation could easily accelerate, bringing VoIP into the mix much sooner than expected based on a grassroots demand set in motion by local entrepreneurs who seek to quickly establish lucrative IP data-based revenue streams.

“The DVB scenario is more suitable for star hub-to-remote broadcast applications, not remote-to-remote. For mesh remote-to-remote applications, proprietary encapsulation and transmission systems are still dominant due to their efficiency,” Fakhari says.

Whether it is used for WLL applications, ISPs, global service providers or corporate Extranets and Intranets, Comsat’s latest addition to the Linkway family of products, Linkway.IP, supports multiple-channel VoIP, and offers what Fakhari describes as flexible user-selectable and definable inbound and outbound rates of 250 kbps to 7 Mbps.

“With Linkway.IP, we envisioned what you might describe as a reverse star topology. We leave it up to the customer to first define the in route, and the out route, and then the customer assigns one of five different data rates on an asymmetrical basis,” Fakhari says. “This is not a typical VSAT. It is designed primarily for multiple content providers in a multi-gateway or multiple-star hubless network configuration supporting VoIP, Web distribution, video multicasting and other applications over IP.”

Fakhari emphasizes that the voice market is awash in legacy protocols, R1 and R2 signaling systems and SCPC systems. “IP-enabled PABXs will start dominating the voice market in one or two years,” Fakhari says.

In mid-April, we interviewed Jose A. Alvarez, director of International Affairs at Maryland-based Startec Global Communications Corp., as he was standing on the floor of the Americas Telecom 2000 conference in Rio de Janeiro. He reported that a lot of people were concentrating on VoIP, cellular VoIP and VoIP via satellite at the show. Major exhibitors at the show who were making VoIP a central focus included Clarent, Cisco Systems and Lucent Technologies, according to Alvarez. Intelsat was there as well doing VoIP demonstrations.

“We have two VoIP via satellite links established in Latin America, and several more are on the table with negotiations well underway,” Alvarez says.

Intelsat’s Internet via satellite road show arrived in Rio de Janeiro to conduct a series of joint demonstrations with several key players. A low-cost C-band interactive multimedia terminal was demonstrated with Alcatel Space and ATC Teleports, using Intelsat 805 at 304.5 degreesE. Intelsat also tapped a Dialaway VSAT from Israel-based Gilat Satellite Networks Ltd. to demonstrate voice and IP services. Finally, to highlight on-demand broadband VSAT services, Intelsat worked with Comsat Laboratories’ Linkway terminals linked to Comsat’s teleport in Maryland via Intelsat 801.

VoIP solutions may not require satellites in each and every instance, but once again, the satellite industry is out front of the curve. By providing customers with a broad array of choices and by pointing these same customers down a series of steps that are designed to address immediate internetworking priorities, the satellite industry is bound to find its phones ringing off the hook.

As Via Satellite’s senior multimedia writer, Peter J. Brown tracks the global satellite industry’s multimedia and Internet applications. He lives on Mount Desert Island, Maine.

---