This article summarizes a flexible, "wideband", point-to-multipoint mobile communications solution that the U.S. Military Sealift Command (MSC) has adopted for its maritime fleet of users accessing the Inmarsat satellite system. It is based on the premise of providing 24x7 connectivity (with asymmetric data rates) to support surge capacity requirements on demand, to/from any vessel, at any time, anywhere in the world. MSC has been utilizing this technique since late 1999 aboard its high usage ocean-going vessels.
Two years ago, MSC, which serves as the logistics and material supply arm of U.S. Naval forces, was utilizing legacy narrowband data and voice services via the Inmarsat satellite system for their ships operating around the world. The MSC predicament was very much that of a disadvantaged remote user in a hard to reach environment – limited access to information due to lack of cost-effective communications services. MSC mission extension demanded the transfer of more information at higher data rates. The new rapid response nature of the 21st century MSC mission had outstripped the ability of the legacy Inmarsat narrowband communications services to keep up with MSC’s information transfer demands.
MSC has a highly remote (ocean-going), dispersed (all ocean regions) and diverse base of users, whose communications performance requirements match those of their U.S. Navy counterparts. Traditional military satellite communications solutions would call for complex and highly expensive architectures that do not make the most efficient use of data throughput potential. MSC budget constraints also eliminated the option for them to implement a "brute force" style and costly "stove-pipe" based solution, with dedicated wideband capacity to/from all of their vessels. The MSC leadership looked for new and innovative solutions to their operational and budgetary challenges.
The BEST Solution
To address its operational and budgetary challenges, MSC chose to integrate the "Bandwidth Efficient Satellite Transport" (BEST) bandwidth on demand virtual private networking solution as an overlay to its existing legacy Inmarsat infrastructure. The BEST solution was developed by Innovative Communications Technologies, Inc. (ICTI) and is operated as a service offering by Stratos Wireless, Inc. (Stratos). BEST’s rapid fielding potential meant that service improvements and cost savings could be realized for MSC early in the implementation cycle.
The BEST solution has achieved efficiencies on the order of 300 percent relative to the legacy Inmarsat architectures (without BEST) previously used by MSC. The annual recurring operating cost for MSC remained virtually the same, while service quality tripled in throughput and changed from periodic narrowband voice or data to full period wideband multimedia voice, data, Internet and Intranet (SIPRNET and NIPRNET).
The BEST system provides MSC with robust service connectivity for voice, data and imagery, both secure and non-secure, for both classified and unclassified missions. In order to implement the BEST product, MSC made a modest capital investment in the initial BEST overlay hardware/software as part of a fleet-wide telecommunications upgrade, which was fully recovered in less than 12 months of regional fleet operations.
Value-added features of the BEST solution include:
•Authorized for use over Inmarsat Lease Satellites
•Based on use of 100 percent COTS (commercial off the shelf)/NDI (non-developmental, custom/ legacy) technology
•Low-risk turnkey solution
•24 x 7 connectivity for all end user terminals at fixed cost
•Rapid deployment cycle (fully operational in less than three months from initial order)
•"Plug ‘n Play" w/ MSC’s existing Inmarsat-B terminals (Nera Saturn-B)
For military users requiring integration with bulk encryption and other legacy devices where the convention BEST point to multipoint solution cannot be seamlessly integrated, ICTI developed a point-to-point fleet-based implementation of BEST that is termed, “Enhanced High Speed Data” or EHSD. The EHSD service provides 128 Kbps full-duplex data rates utilizing the same 100 kHz Inmarsat lease capability normally allocated to provide 64 Kbps legacy high speed data (HSD) service and includes an integrated fleet management option that allows for dynamic allocation of bandwidth (ranging from 16-256 Kbps in 16 Kbps steps) from a centralized administrative facility at any node in a user’s global network.
he EHSD service is quickly initiated with the simple installation of ICTI’s 1U, 19-inch rack mountable “Intelligent L-Band Modem or INT-L-Modem with remote Inmarsat-B terminal.
BEST Coverage Map
The BEST service coverage is illustrated in Figure 1, note that a 142W satellite will be available for service in March 2002. The four satellites that provide this coverage comprise the Inmarsat Lease Satellite Constellation.
MSC BEST Network Configuration
MSC operates its BEST network in a point-to-multipoint configuration in each ocean region, with a large (128 Kbps to 1 Mbps) shore-to-shore (forward) link and dynamic (variable) ship-to-ship (return) links ranging from 8 Kbps to 256 Kbps on-demand.
Terrestrial lease links are installed between the Stratos Land Earth Station (LES) and the designated MSC shore-side data center or point of presence (POP) in each ocean region. The dynamic data rates can be set up in the return direction through the Bandwidth Management Console (BMC) Server located at each Stratos LES or the remote user interface (RUI) client located at each MSC POP (working hand-in-hand with its respective BMC). In this manner, a combination of enhanced, as well as “non-channelized” services can be provided for MSC users that desire to capitalize upon and manage bulk power/bandwidth resources on their own.
The BEST service proposition includes 24x7 operational support by Stratos personnel at all Inmarsat lease satellite LESs, as well as multi-level 24x7 technical support, by both Stratos and ICTI personnel, as necessary.
BEST Management System
The BEST service provides MSC users and decision-makers with a fully managed network solution. It includes management facilities that display real-time views of the entire network, across all ocean regions, as well as a means to dynamically re-allocate bandwidth to users in the manner that MSC managers see fit, commensurate with varying mission requirements and user priorities.
A remote version of these management facilities is implemented via the RUI client suite of software applications at each MSC POP.
Specifically, the RUI allows MSC managers and administrators to gain access to the following remote management functions and services:
-- View network equipment status (Inmarsat terminal equipment, BEST KIT, LES modems).
-- View bandwidth/data rate allocations in place at any point in time by terminal ID.
-- Pre-plan bandwidth allocations and post to database for execution at future time.
-- Ad hoc modification of bandwidth allocations for immediate execution.
The BEST service utilizes advanced network and bandwidth management algorithms performing concurrent applications for enhanced service functions such as non-interference safety measures, delivery of remote site configuration parameters, network monitor and control, and dynamic bandwidth allocations.
These functions are hosted by the BMC server and are remoted to the RUI client application. On the remote node site, each BEST Kit runs the BMC client software that interacts with the shore-based management systems.
The end result is more efficient utilization of capacity by accommodating the subset of users requiring higher data rate full-period connectivity at lower data rates to that subset of users not requiring a surge capability at the same time.
MSC Concept of Operations
Military Sealift Command provides BEST-managed Inmarsat service to 30 vessels in the Atlantic, Pacific and Indian Ocean theaters. As vessels are commissioned, deployed or moved between ocean regions, MSC can easily and rapidly provide connectivity for system acceptance and training, or operational assignment. The ability to conduct system acceptance and training using easily allocated segments of capacity has meant dramatic savings over the alternative of keeping Inmarsat leases on hand for contingency.
During day-to-day operations, MSC can allocate periodic increased data rates for individual ships needing to transmit large data or imagery files. This is accomplished without any interruption of the forward broadcast and only instantaneous interruption of the return carriers undergoing data rate change.
MSC has also developed a deployable van version of BEST that will enable land-based users to immediately arrive at a port of interest and establish full voice and data connectivity to hit the ground running in support of MSC fleet missions.
MSC will continue to field BEST systems as its communications requirements expand. By using BEST, Military Sealift Command has fulfilled current communications requirements while using significantly fewer leases than required with the IT-21 HSD (Information Technology for 21st Century Inmarsat High Speed communications matrix) program. MSC can respond to numerous high tempo variations within existing network resources without committing additional financial resources for emerging missions.
In short, BEST positions Military Sealift Command to meet future requirements with less bandwidth. In the high cost bandwidth-constrained Inmarsat environment, this results in better communications at lower cost.
Ken Toy is in the Military Sealift Command, Afloat Systems Division. M.G. Abutaleb is president of Innovative Communications Technologies.