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CHIPS Articles: IRIS

Changing the fixed-circuit paradigm
By U.S. Navy Lt. Cmdr. Tom Merkle, Rich Farrell and Steven Groves - July-September 2009
U.S. Navy and Marine Corps command, control, communications, computers and intelligence (C4I) communities face a major obstacle in fielding a true net-centric capability to the warfighter due to inadequate throughput to disadvantaged and remote users. But help is on the way.

Industry partners, in collaboration with the Defense Department, will launch and operate the Hosted Payload-Internet Routing in Space (IRIS) on Intelsat's IS-14 satellite scheduled for launch from Cape Canaveral in late summer 2009.

Since IRIS is a commercially owned and operated venture, the cost of the satellite, launch and payload are funded by a private sector group, led by Cisco Systems Inc. and Intelsat General Corp.

IRIS represents the next generation in telecommunications satellite services with an ability to reach into space. IRIS will cover Europe, Africa and the Americas from its 45-degree orbital slot over the Atlantic Ocean.

The IRIS payload will provide the ability to merge ground and space communications infrastructure with Internet Protocol (IP) — the common frame of reference between networks. Figure 1 illustrates the IRIS topology.

U.S. Strategic Command has tasked Army Space and Missile Defense Command Future Warfare Center (SMDC-FWC) in Colorado Springs, Colo., with determining if a commercial Internet hub in space would dramatically improve net-centricity for strategic, operational and tactical units of the DoD, and joint, interagency, intergovernmental and multinational (JIIM) partners.

To this end, experts from SMDC-FWC are monitoring, collecting and assessing data associated with the IRIS venture during pre-launch preparations. They will also conduct a final operational demonstration after the IRIS package is on orbit.

The IRIS Hosted Payload program was accepted by the Defense Department as a fiscal year 2007 Joint Capability Technology Demonstration (JCTD). The demonstration will examine the potential utility of augmenting joint, interagency, intergovernmental and multinational information transport with space-based IP routing and processing.

The IRIS JCTD represents a new model for government and industry collaboration. This relationship will allow the DoD to examine, demonstrate and assess the utility of IRIS' capability and potentially transition this capability to U.S. forces both at home and abroad.

The IRIS JCTD will provide an operational utility assessment and a recommendation to the Office of the Secretary of Defense regarding the operational impact of the IRIS venture. If IRIS has utility for the DoD and JIIM community, the JCTD will execute a contract mechanism for the De fense Information Systems Agency (DISA) to procure IRIS services.

On-orbit assessment of the IRIS payload begins fall 2009. The primary players for the on-orbit assessment are Joint Interagency Task Force (JIATF) South in Key West, Fla.; U.S. Southern Command in Miami, Fla., and elements of the Royal Netherlands Navy (RNLN), including Commander Task Group 4.4 in Curaçao, Netherlands Antilles.

Testing during counter-narcoterrorism operations in the JIATF South operations area is scheduled to be conducted both ashore and underway on the Royal Netherlands Navy warship HNLMS Amsterdam (A836).

The SATCOM Bottleneck

Much has been done to increase available bandwidth and throughput via military satellite communications (MILSATCOM); however, the gap between end-user requirements and available capacity is growing faster than anticipated. No significant reduction in this gap is expected to begin until the next generation of MILSATCOM is available. In the meantime, military forces must either accept the disparity between requirements and existing MILSATCOM capacity, or shift throughput to commercial satellite providers.

Between 60 to 80 percent of all DoD satellite bandwidth in the beginning stages of Operations Iraqi Freedom and Enduring Freedom was provided by commercial satellite. COMSAT proved to be an important part of providing connectivity to the warfighter. However, the longterm cost of commercial satellite service remains prohibitive.

The COMSAT market has also become tighter in recent years because new users have emerged and companies and governments worldwide have increased their use of services at a faster pace than new capacity has been added.

In addition to the high cost, there is another constraint: Most COMSAT services are provided through a "bent-pipe" architecture. This means that data transmitted to the satellite is sent right back down like a bent pipe to fixed gateways to the Global Information Grid (GIG) on the ground. The only processing done by the satellite is to retransmit the signal. The gateway architecture creates throughput problems because different sized military units use varying satellite systems, frequencies and gateways to access the GIG.

This smorgasbord of systems requires multiple frequency conversions, digital processing, routing via terrestrial networks and additional satellite links between distant ends. The result is that IPbased network traffic between a flagship and a destroyer just a few miles away may require multiple hops through different satellites and ground networks prior to arriving at its destination.

Each of the steps adds delay and latency and lowers effective throughput, especially to small disadvantaged units.

Bottlenecks Affect Missions

The resulting low throughput makes it difficult to provide shore-based networks and network enclaves, such as the classified SIPRNET, to the small maritime unit. The DoD has been able to overcome some aspects of this problem via Web-based tools such as Collaboration at Sea.

CAS is based on the IBM/Lotus collaboration toolset and is used mostly to support operations with coalition partners. CAS and other network traffic reduction methods have helped to integrate the small unit into the networked battle. However, there is no solution for high throughput requirements at the heart of net-centric operations, including transmission of high-resolution imagery, fullmotion video and video teleconferencing for telemedicine.

This C4I bottleneck is daunting enough for traditional U.S. command and control networks, but it intensifies when integrating multinational organizations and governments, interagency partners, and military coalitions and allies of varied technological and financial resources.

In general, multinational organizations and coalition partners cannot afford to devote sparse satellite bandwidth to multilateral networks such as the Combined Enterprise Regional Information Exchange System (CENTRIXS.)

This makes tasks that are taken for granted at a land-based headquarters insurmountable for deployed ships and small units. For example, simply e-mailing a photo of a suspect vessel to a coalition warship on patrol may be impossible or so delayed that tactical value is lost.

The Fixed-Circuit Paradigm

There are two main reasons why small and disadvantaged units experience low throughput: a rigid satellite subscription fee structure and large antenna size. The bent pipe architecture requires a continuous, fixed satellite link between the gateway on shore and the forward-deployed unit when the circuit is connected.

Since the frequencies, channels and power amplification that a single COMSAT can support are fixed at launch, the cost of the satellite and launch is recovered in the access fees paid over the life of the satellite. The architecture also generally requires large, bulky antennas and even multiple antennas for multiple bands.

Bent pipe communication channels must be reserved ahead of time and cost the same regardless of the amount of data passed over the transponders. Whether a unit uses 90 or 10 percent of the licensed throughput, the full channel is reserved.

Even mobile systems, such as Inmarsat B, require that the circuit be dialed in and fully "on charges" to be connected. This results in a high cost of doing business for deployed units, ships, combatant commanders and the shore-based communication providers that support them.

To keep the cost and antenna size to an acceptable level for various commercial and government customers, the COMSAT industry provides the minimum acceptable throughput for the majority of its customer base. For example, Inmarsat B provides voice services, telex services, medium speed fax and data services at 9.6 kilobits per second (Kbps) and high speed data services at 56, 64 or 128 Kbps.

To minimize cost, combatant commanders and communications planners provide COMSAT access only to the tactical units that are deployed on a day-today basis. However, network throughput requirements can vary dramatically over the course of a day and even over the course of an hour. During a crisis or surge period, a narrow channel presents the same slow response time and the same low throughput regardless of need.

Meanwhile at low demand times, the full channel is being maintained but underutilized — at the same high price. Another complication arises in preparing for a surge or contingency requirement. The lead time for commercial satellite service provisioning is considerable. It can range from several months to several years in advance.

In the event of a critical requirement, there may not be sufficient channel availability in the crisis area to provide services to deployed ships and units.

Communications architectures using IRIS have the potential to overcome many of these issues. By providing digital processing on orbit and multiple bands of service, the IRIS payload can reduce antenna size requirements, particularly for maritime units.

But, the most important IRIS capability lies in the promise of dramatically better flexibility for requirements planning, lower overall cost per bit and a higher throughput to the disadvantaged unit.

If the IRIS payload is able to deliver on these promises, the result would be improved connectivity, more affordable bandwidth and more flexibility in operations with JIIM partners.

Changing the Paradigm

Lack of flexibility is a problem with fixed-circuit paradigms, whether satellite or land-based, and it has a major effect on the cost of bandwidth. For a comparison with land telephony, consider the difference in cost between an Internet service provided T1 line versus a 1.5 megabits per second (Mbps) digital subscriber line.

Whereas the T1 line averages $500 to $600 in cost per month, DSL from the same company averages $50 to $60 per month for the same throughput.

The difference in price is primarily due to oversubscription which allows underutilized bandwidth to be shared among users. Since not all customers require the full 1.5 Mbps throughput at all times, a telecommunications provider can provision much less total throughput on the back-end than a fixed circuit would require.

When applied to satellite services, under the current fixed-circuit paradigm, providing services for 40 satellite customers at the relatively low rate of 128 Kbps requires 40 different channels for a total satellite throughput of 5.12 Mbps.

On the other hand, with modest oversubscription ratios of 5-to-1 or 8-to-1, that same 5.12 Mbps of satellite capacity would allow 10 512 Kbps channels, which can support between 50 to 80 customers, and yet each customer would effectively experience the higher rate of 512 Kbps.

More customers can be serviced at a far higher throughput. In addition, since customers use the system on demand rather than continuously, they can be charged on the basis of actual data services used, rather than access fees.

This concept has been difficult to implement for traditional bent pipe satellite services due to the high latency between the distant end and gateway and the larger antenna size that a higher bandwidth connection requires. By reducing antenna size and harnessing the inherent flexibility of IP routing, a COMSAT with IRIS capability could eliminate the resourcing and scheduling difficulties of provisioning adequate throughput for contingency and surge requirements.

IRIS Operational Demonstrations

The IRIS JCTD has already performed two of four planned operational demonstrations. Because OD 1 occurred prior to satellite launch, it focused on characterizing space router performance, which was emulated at MIT's Lincoln Laboratories in July 2007.

In preparation for the maritime and terrestrial nodes required for demonstration, SMDC-FWC and the U.S. Coast Guard Pacific Area conducted OD 2 in September 2008. USCGC Sherman (WHEC-720) used existing domestic Ku-band satellite services and simulated the IRIS payload on land at a San Diego teleport. The simulation effectively quadrupled the available throughput using the same size antennas the Sherman uses with its existing legacy SATCOM service.

The Sherman became the first cutter to perform a high-quality video teleconference between ship and shore, including a live video interrogation of an individual of interest on the ship by an interpreter based on shore.

The critical lesson learned was that linguists could be based anywhere in the world and conduct a real-time interview of a suspect in custody on an underway vessel.

The ship was also able to rapidly upload and download multiple large PowerPoint files, images and documents, which required huge amounts of bandwidth, proving that the increased throughput could improve operational planning and communications.

The final demonstration is scheduled for fall 2009. It will test the performance of on-orbit IRIS services and the operational impact of an Internet hub in space for secure and multilateral IP-based networks. The test will involve communications between multiple land sites across the Caribbean and aboard HNLMS Amsterdam.

The key land nodes are JIATF South, USSOUTHCOM and Commander Task Group 4.4 headquarters. The demonstration will include providing tactical data and services to the HNLMS Amsterdam that are currently available only to shore-based sites.

The tactical data are expected to enhance the capability of the HNLMS Amsterdam to support counter-narcoterrorism operations in the JIATF South area of operations. Capabilities include coalition encrypted CENTRIXS, a live video broadcast of the daily situation briefing, video teleconferencing, Voice over IP, and transfers of daily operations briefs and images usually only available to shore-based networks. The Amsterdam crew will also enjoy robust Internet access at sea.

The Road Ahead

As Internet and networking technology continues to proliferate on a global scale, commercial Internet hubs in space like IRIS will likely become commonplace.

Once IP routers are deployed on geostationary commercial satellites, a truly net-centric capability may be available to the disadvantaged and small maritime unit for the first time.

Lt. Cmdr. Tom Merkle is the chief for C4I systems engineering for JIATF South.

Mr. Rich Farrell is a senior analyst with Camber Corp. providing support to SMDC-FWC.

Mr. Steven Groves is a lead scientist with Camber Corp. providing support to SMDC-FWC.

Figure 1-Intelsat 14 illustration
Figure 1.
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