The Future for Satellite Technology

Although traditional VSAT technology, with its minimal uplink bandwidth, is not appropriate for some organizations, the newer systems in development should be reviewed by network architects. For example, Hughes' new system under development, the Spaceway system, is expected to provide a variety of low-cost broadband services with small satellite dishes, with data rates ranging from 512 kbps upstream and up to 30 Mbps downstream. Applications will include Internet access (with a strong multimedia component) to LAN/ WAN solutions for work-at-home employees, SOHOs, and large organizations.

Hughes' system includes full mesh point-to-point and multicast communications architecture. This allows the development of high bandwidth peer-to-peer applications, such as file sharing, distributed databases, and decentralized content distribution.

The availability of reasonably fast Internet links in rural areas around the world could significantly change the business dynamic of many firms. While the media continually laments the lack of bandwidth, the most serious deficiency of the Internet is actually the lack of geographic coverage.

Another alternative architecture is a hybrid system that uses satellite transmissions for downlink and terrestrial for uplink (currently used to provide Internet access to areas with no other broadband availability). Because satellites are large (many tons), they have power plants that allow megabit-per-second downloads of video, software upgrades, and other information. The terrestrial link in this asymmetric data access scheme provides for less latency (delay) for the user response. Most applications, as is the case with home Internet users, consume far more download bandwidth than upload bandwidth.

The technology of caching will be increasingly used for Internet services. Caching takes recently retrieved information, copies it, and places it on a server close to the consumer. This process allows users to access popular Internet data quickly because it is physically located much closer to the user. The more users are associated with a cache, the more the benefit because there will be a higher likelihood that a requested file will be in the cache. This could potentially speed the deployment of international intranets for global organizations. Caching is relevant to satellite transmissions because it reduces demand for repetitive uplinks from the hub for frequently used pages.

Controls to Improve Resiliency, Reliability and Security | Satellite Communications

Good practices can mitigate some of the risks associated with satellite communications. Firms that have all their offices or plants linked via satellite/ VSATs should carefully consider the exposures. For example, one paging company suffered customer ill-will and economic loss because the satellite it was using to relay pages stopped functioning. The following description of a satellite breakdown and its consequences is courtesy of 911 magazine (August 1998,

The Day the Pagers Went Silent

When the PanAmSat Galaxy IV Communications Satellite got knocked out of its orbit for a couple of days in May, it also knocked out the majority of pager communications in the United States.

Launched in 1993, the $250 million HS-601 spacecraft stopped relaying pager messages, television news feeds, and all sorts of broadcast data communications around 6PM PST on May 19th when the satellite's onboard control system as well as a backup switch failed and it rotated out of its proper position. PanAmSat, which owns the satellite, scrambled to establish communications with the Galaxy 4, finally re-establishing its position on the evening of the 20th. That affected thousands of emergency communications centers nationwide, which depend on pagers to notify responders and senior staff of emergencies

"I would hope that in the future, this type of failure will be automatically corrected by electronic or computer means without having to manually redirect antennas or reprogram computers," said Miami's Charles Manetta. "This is how many telephone failures are corrected and are transparent to the end user. Time will tell."

The failure was not without irony. The Phoenix Disaster Recovery Newsletter reported:

For several hours after the spacecraft failure, the president of PanAmSat tried desperately to get in touch with Hughes' technical team in charge of engineering for Galaxy 4. After more than 3 hours, he finally contacted GM senior management (owner of Hughes, of course) by telephone. He said he'd been trying to contact Hughes' techno geeks for hours. "Why," he demanded, "didn't your people respond to my pages?"

Had a contingency plan been in place (including alternate satellite), resumption of service would have been quicker. Following are some of the most common control and security measures employed for VSAT satellite systems:

  • Change control. Both the remote VSAT dishes and the central hub are attached to a myriad of software and hardware support systems. For example, central hub operators, including providers such as Hughes Global Services and Gilat Satellite Networks Ltd., must be extremely careful with the software that controls repositioning of the hub dish. Otherwise, an error could cause the signal to become so attenuated that communication would stop. Of course, the usual communications infrastructure, including hubs, routers, and network management software, should also be included in change control. Occasionally, perhaps once per year or every six months, hubs need to be brought down for maintenance (physical and software upgrades). This schedule should be published well in advance.

  • Equipment redundancy. Spares for critical equipment such as the IP gateway (links the organization's LAN/WAN to the satellite system), specialized modems, encryption boxes, and other satellite-specific devices should be available and periodically tested.

  • Backhaul redundancy. The backhaul circuit is usually a terrestrial communications link, such as a T1 or Frame Relay circuit, that connects one or more central locations to the satellite hub. If this link is cut by a backhoe or loses function for some other reason, communication is lost. Hence, a duplicate circuit, perhaps from a different long-distance provider, but at least in a different conduit, is required.

  • Power. For redundant equipment that is on hot standby, a separate power source provides protection from power supply failure. For example, a dual 250W hot-swap redundant power supply may be required for some devices.

  • Backup arrangements. Satellites are expensive. The launch alone is typically $50 to $400 million, with costs further exacerbated by occasional launch failures. As a result, satellite transponder space is at a premium. Organizations relying on satellite communications for critical business functions cannot assume that they can "throw money" at the satellite vendors and get backup service quickly. Much of the capacity is booked months, even years in advance. Spare capacity should be obtained in advance of need.

  • Disaster recovery planning and testing. In addition to negotiating with their satellite provider for backup capacity, organizations need to carefully design their response to a satellite failure. VSAT dishes will most likely need to be repositioned in every office or plant using the service. The whole reason for having a satellite remain geo-stationary is that the field dishes can be set and locked to look at a specific point in the sky. Practically, it may take weeks for a large network of VSATs to get repositioned and correctly adjusted, because a trained technician must do the work.

  • Service level agreements (SLAs). Service level agreements should be established for the hub operator, satellite service, and dish maintenance vendor. Frequently, the hub operator and dish maintenance vendor (for field locations) is the same provider. SLAs are particularly important for satellite failure because that is the most difficult step in recovery. If, for example, backup transponder space has been purchased on the same satellite, then the SLA should state how long it will take to transition operations. From the perspective of the field office or plant, what is the response time for dish or RF (radio frequency) equipment problems? Chart below summarizes key issues to be addressed in satellite service level agreements.

  • Capacity planning. While the downlink bandwidth (satellite to VSAT dish) can be quite large, the uplink is often no more than could be expected from a terrestrial modem and sometimes less. As more VSATs are added, the uplink capacity of the system will degrade unless more "in-routes" or uplink bandwidth is added. If an organization has specific bandwidth needs that are highly likely to occur, it should consider purchasing extra transponder space so that there is no delay when the need arises.

  • Network Management System. Components of the satellite communications system should be SNMP (Simple Network Management Protocol) addressable so they can be monitored along with the rest of the organization's communications infrastructure.

  • Physical/electrical protection. For VSAT dishes, a lightning arrestor and surge arrestor are de rigueur. Trees, bushes, and other obstructions can interfere with the line-of-sight. Often when the dish is installed, adjacent trees are small but with growth they steadily decrease the signal strength. Access to the facility should be restricted as well.

  • Expertise. For those firms with enough VSATs to justify owning their own hub — an investment in excess of $1 million — highly skilled technicians are required. Backup personnel (perhaps including contractors) should be available.

  • Spare parts. Particularly for hub operators, spare parts will prevent delays in operations.

  • Documentation. As in other complex systems, documentation of frequencies, sites, IDs, network schematics, etc. is important. Firms operating their own hubs need to pay particular attention to documentation because of the inevitable drift toward technical uniqueness.

Call Centers

There are a number of technology solutions that can reduce overall organizational costs, even if they add slightly to the telecom budget. Call centers provide one such solution.

Call Centers

Although call centers would be an obvious choice for heavy massing of technological firepower, many organizations still rely too heavily on human agents to do work that could be done by computers and telephone systems. Examples include:

  • Predictive dialers. Anathema to families that enjoy a quiet dinner together without telemarketer interruption, predictive dialers allow agents to call efficiently. Not only does the predictive dialer actually make the call, but it "uses complex mathematical algorithms that consider, in real-time, the number of available phone lines, the number of available operators, the length of an average conversation and the average time operators need between calls, and constantly adjusts their dialing rates based on these factors." Also, the best predictive dialers screen out calls where there is no answer or those that are answered by an answering machine. Most of the time, the calling agent hears a quiet "zip" in the headphone and a live person is then on the line. While manual dialing may result in 15 to 20 minutes of productive calling time per hour, predictive dialers allow agents to productively talk 40 to 57 minutes per hour. Given that call center agents are paid between $12 and $20 per hour (as well as incentives), any device that makes them more efficient is likely worth the investment. It is interesting to note that, in the eternal war between "push" or outbound call centers and potential customers, technology solutions are found on both sides. Telemarketer "zappers" are now sold that intercept telemarketing calls. In Texas, some 77,000 households have signed up for a blocking service since the law went into effect on January 1, 2001.

  • Call center workforce management software. Although scheduling agents via software would seem to be a "nice to have," akin to a deluxe PDA, it strongly affects call center costs. Beyond a certain number of agents, it becomes difficult to mentally juggle schedules, demand, holidays, incentives, shifts, etc. One of the highest expense items is overtime; without an automated system for scheduling and reporting, absenteeism and overtime will climb to unacceptable levels (for mid- to large-sized call centers). Steven J. Cain, Gartner Group's Call Center Benchmarking Practice Research Director, says that, "When you consider that, in some industries, contact center turnover reaches as high as 50 percent, there is significant opportunity to reduce turnover, building an experienced and tenured agent base to deliver the highest quality customer interactions while minimizing the expense of recruiting, training and productivity shortfalls while getting up to speed."

  • Interactive Voice Response System (IVR) The familiar "press 1 for account balances, press 2 to transfer funds," is the public face of interactive voice response technology. Some call centers shun IVR systems because of the acknowledged public preference for human interaction. This philosophy should be reconsidered in some cases. For example, is it better to staff from 7 a.m. until 10 p.m. and then leave a message for the customer to "call back during business hours" or to have an IVR after-hours that provides the customer with some useful information. Second, as the public becomes more familiar with IVR, there are situations where non-human interaction is faster and preferred. For example, when people call about booking reservations for deluxe resorts, they want to talk to someone and ask multiple questions. However, if they must cancel those reservations, they merely want to cancel — why take the time to explain? In this case, the transaction can be handled without agent contact, saving money for the company and time for the customer.

Risk Areas for Satellite Communications

Experienced VSAT technicians are often loath to quote satellite reliability above 99 percent availability. Key risk factors for service interruption include the following:

  • Rain fade. Normal or even reasonably heavy rain will not necessarily disrupt communications. However, a heavy downpour can weaken the signal so much that transmission stops. The hub operator can adjust power on the hub to a certain extent but at some level of rain, nothing more can be done. As expected, some areas of the United States are far more susceptible to rain fade than others (e.g., some parts of Florida).

  • Satellite malfunction — fuel shortage. While any number of destructive elements, such as meteorites, can disable satellites, they are most commonly rendered useless because of fuel shortages. A geosynchronous satellite must necessarily stay within tight limits of position in the sky because all VSAT dishes must be fine-tuned for direction to ensure a strong signal. And because satellites naturally tend to wander in an elliptical path, they must be constantly homed to the correct position in space via small thrusters mounted at appropriate locations around the outside surface. These thrusters require fuel; when there is no more fuel, ground control is unable to keep the satellite on target and it drifts away, thus becoming useless for communications. There is a story about the early days of commercial satellites in which technicians new to satellite management used a mouse hooked to a control unit to position the "bird." Apparently, it was so much fun that they moved it around too much, depleting its fuel and rendering a multimillion-dollar satellite useless.

  • Satellite malfunction— transponders. Transponders receive signals on the uplink, translate them to the downlink frequency, and amplify them for retransmission to Earth. Transponders can and do fail. Because there are multiple transponders in a satellite, the failure of a single transponder does not necessarily mean the end of the satellite's life. However, if an organization's communications are going through the failed transponder, the result is the same as if the satellite had been knocked out — that is, no service for that organization.

  • Ice and snow. If VSAT dishes are not properly heated or enclosed in a radome (special purpose plastic cover), they may not receive and transmit a sufficiently strong signal to function.

  • Lightning and power surges. Engineers working day-to-day on VSATs generally agree that the most frequent reason for breakdown of the dishes is electrical.

  • Relatively short mean time to failure. VSAT equipment stays hot and wears out relatively quickly.

  • Frequency conflicts. Although the FCC controls the frequencies used, occasionally a technician will set up a VSAT incorrectly, resulting in interference. The solution is for all parties to return to their assigned frequencies to avoid interference.

  • Sun transit errors. When the main beam of an Earth station receiving antenna is in a straight line with the sun, significantly larger noise will occur, sometimes temporarily stopping communications. These errors are more likely to occur during the fall and spring equinox. Sun transit problems are far more likely to occur with the older, type I VSAT dishes. Type II and III dishes are smaller in diameter and less sensitive to concentration of noise.

  • Temporary "commandeering" of frequencies by government authorities. For purposes of safety and security, government authorities or military personnel may temporarily take over certain frequencies in a geographical area. These are lawful actions but in some cases organizations using those frequencies are not timely notified and spend considerable time researching the cause of the downtime.