VSAT Requirements Planning
Reliable communications for remote camps, vessels at sea, or SCADA/M2M applications is often critical to business operations. Whether it is to expedite business processes, ensure the safety of staff in remote locations, enable remote workers to keep in touch with the office and family, or enable automated remote management of equipment; these goals are difficult to achieve absent a reliable communications link.
VSAT (Very Small Aperture Terminal) satellite communications provide reliable Internet communications to accommodate both business data applications and voice communications at remote locations around the globe. As with any complex project; proper planning, professional implementation and on-going support of your VSAT communications are critical success factors. Step one is the effective definition of your communication requirements.
The information below is provided to assist you in planning a successful VSAT system implementation that will meet your requirements for performance, availability and reliability. Your investment of time to work with Network Innovations to mutually define your VSAT system requirements will result in a higher level of success for your remote communications.
As a primer, some basic information on typical VSAT configurations is provided. The picture to the right depicts a typical configuration consisting of remote VSAT units at field sites which communicate via satellite back to a Hub & Teleport, which in turn provides the connection into terrestrial infrastructure (the Internet, private backhaul, the PSTN telephone service). Most customers will leverage the use of Network Innovations’ (NI) terrestrial infrastructure options, but for large scale deployments of dozens or hundreds of remotes, it may make sense for the customer to own and operate the Hub infrastructure.
VSAT Network Topology
VSAT networks are typically Star or Mesh configurations. In star topology, each VSAT terminal transmits and receives only to the hub/teleport which then interconnects to public infrastructure. VSAT remote stations communicate amongst themselves via the hub. The majority of VSAT networks use star topology because the large antenna gain at the hub optimizes the use of the satellite space segment and thus minimizes the size and cost of the VSAT terminal required at the remote site. The drawback of star topology is that the delay for VSAT to VSAT communication doubles in comparison to single hop transmission.
Mesh topology allows all terminals to communicate with each other directly. A hub must control the communications process, but need not be involved in carrying traffic. Hybrid topology allows a group of VSAT terminals to communicate in mesh topology while others communicate only in star topology.
The VSAT equipment for the remote site will vary in terms of the size and power of the equipment and the type of antenna (fixed, portable, auto-tracking), however the typical components of a fixed site are depicted to the right.
The outdoor equipment consists of an antenna which can be mounted on a pole or can utilize a non-penetrating roof mount (NPRM) to enable mounting on a roof or the ground, secured with cinder blocks as ballast to ensure the antenna doesn’t move.
The VSAT antenna sends and receives signals via the feed horn assembly, LNB (low noise blocker) and BUC (block up converter). The size of the antenna and BUC will vary depending upon the frequency in use and the link budget for the specific site. A link budget calculates the power and antenna size required to provide the desired level of bandwidth to a specific site based upon the site location, satellite in use and size/type of equipment at the Hub/teleport.
The indoor equipment will consist of a satellite router along with other LAN equipment that may be required for your remote site.
VSAT bandwidth is available in different frequency bands. The most common bands for commercial applications are: C, Ku and Ka. The main differences between the various bands is the size of equipment, performance & reliability in poor weather conditions, and commercial or consumer grade levels of service related to user subscription/contention levels.
C Band is preferred for climates that have heavy rainfall, as it is the least susceptible to rain fade issues. C band antennas are typically 1.8 to 2.4 meters in size. Ku is the middle ground in terms of rain attenuation and antenna sizes; typically 1 to 1.8 meters. Ka is the most susceptible to rain fade issues but provides the smallest antenna sizes and lowest cost of equipment.
Advances in Adaptive Coding Modulation (ACM) help to mitigate rain attenuation by changing the modulation on the fly to maintain reliable connections in poor weather conditions.
Historically, commercial grade services have been based upon C and Ku band for reliability purposes. Ka has been popular in consumer grade services given the less critical nature of consumer communications and the need for lower cost equipment in the consumer market. However, most satellite operators are beginning to deliver commercial grade Ka services. Consumer grade services suffer from high contention ratios (the service is over subscribed in order to make it low cost) and harsh fair access polices (FAP) which restrict the amount of data that the user can send or receive. NI’s VSAT services are commercial grade to provide optimal performance for business applications.
|C Band||Ku Band||Ka Band|
|Cost of Equipment||High||Medium||Low|
|Cost of Bandwidth||Medium||Medium||Low|
|Size of Equipment||Generally 1.8-2.4m Reflectors||Generally 1.2m||Generally .98m|
|Auto-Pointing Technology||High Cost||Medium Cost||Medium Cost|
|Rain Attenuation||Least susceptible to rain fade||Low susceptibility to rain fade||Medium susceptibility to rain fade|
TDMA/SCPC – Shared or Dedicated Bandwidth
VSAT bandwidth can be procured as either shared bandwidth (TDMA – time division multiple access) or dedicated bandwidth (SCPC – single carrier per channel). Dedicated bandwidth means that you are not sharing with other users, so if you purchase a 1 Mbps up/downlink, that is the actual speed you will realize for communications. With TDMA there are variances which can make it complicated for customers to compare rate structures between various vendors.
When TDMA services are provided, it is the hub operator who establishes the contention ratios and they may choose to share or not share that information with customers. Additionally, some VSAT hubs employ frequency hopping, which is dynamic load balancing, and that can make the concept of contention ratios less meaningful in terms of understanding what level of service you are procuring. For example, a 2 Mbps down/512 Kbps uplink plan at 10:1 contention level would mean that your peak/highest performance you would see would be 2 Mbps down and 512 Kbps uplink, but since you are sharing that with ten other sites, you are only assured of 10% of that bandwidth during times of heavy usage. Additionally, you have no say in which ten other sites you are in a sharing pool with, so pending usage patterns you can expect varying performance with TDMA based services. Network Innovations provides monitoring services which enable both you and our NOC to ensure that you are receiving the bandwidth performance that has been promised by the satellite hub/teleport operator.
Committed Information Rate (CIR) can be added to TDMA services to provide minimum performance levels. For example, Voice Over IP (VOIP) telephone calls will need anywhere from 20-40 Kbps, up & down link, to ensure a reasonable quality of service for a telephone call. Users can pay for CIR to ensure the necessary bandwidth is always available to support applications that have acceptable levels of bandwidth over which they can reliably operate.
The other components of your VSAT solution will be the LAN equipment that you use at the remote site, which will likely consist of switches, routers, VOIP telephones, Wi-Fi access points, filtering devices and packet shapers to provide connectivity for voice and data communications and to ensure optimal performance and efficient usage of your VSAT bandwidth.
VSAT licensing varies from country to country. This will include import duties, taxes and then annual fees for a VSAT license with the regulatory body of the country in question. In some cases you may be able to fall under a blanket license agreement of the hub operator. This is the case for most NI customers in Canada and the USA. If you are not able to use a blanket agreement then your timeframes for obtaining a VSAT license could be 2-6 months pending the country in question and how long it takes them to provide license approval. Countries with restrictive political regimes may deny you a VSAT license, so it is imperative to begin your licensing application process early, so as not to impede your implementation timelines.
Capital cost for your entire VSAT configuration may be as low as $5,000 or could be tens of thousands of dollars depending upon the scope and scale of your requirements. Operating costs for monthly fees for bandwidth and support services can range from $250 to $50,000 per month, again depending upon bandwidth requirements. It is important that you provide NI with some frame of reference for the budget that you are working within so that expectations can be set accordingly as to what can be delivered within your budget parameters.
Geography & Site Location Requirements
The geographic location of your sites will have a bearing on which satellite(s) NI can select from to provide optimal bandwidth to you. Ensure that you have the GPS latitude/longitude of your remote sites and inform NI of any potential issues that might impede line of sight (E.g. heavy tree canopy or in a canyon). NI can perform a site survey to confirm look angles or you can utilize SmartPhone Apps that allow you to confirm clear line of sight to specific VSAT satellites.
Other pertinent issues related to your remote sites include:
- Interference – Inform NI if there are any other type of satellite or radio equipment transmitting at the site which could potentially cause interference.
- Mounting – Depending upon where you intend to mount the VSAT system (on a pole, on the ground, on the top of a trailer or building), a suitable pad or pole will need to be installed for the VSAT antenna. If it is to be a mounted with a Non-Penetrating Roof Mount, you’ll need to provide 500-1,000 pounds of ballast (e.g. cinder blocks) at the remote site.
- RF/Power Cable Run – Measure how long the cable run length will be from the proposed location of the antenna back to the building that will house the indoor equipment (VSAT router, etc.). Consider whether the cabling will need to be trenched.
- Power Source: The site will need AC or DC power via a suitable generator and a UPS system with battery backup will be required to protect the VSAT equipment from power damage.
Weather Patterns/Frequency Band
The type of weather that you experience at the locations of your VSAT systems will have a bearing on which frequency band should be used for the site. Inform NI if your VSAT site location experiences heavy rain or snowfall on a regular basis. To ensure the right outdoor equipment is selected, ensure that you inform NI about any extreme high/low temperatures for the site location.
VSAT antennas are available as fixed units, fly-away portable units and mobile vehicle-based units with optional auto-pointing controllers. Installation of a standard VSAT antenna requires a trained technician with the proper equipment (e.g. spectrum analyzer) to ensure optimal service. For this reason most mobile applications tend to choose an auto-pointing controller unless the customer has trained staff that can successfully point a VSAT antenna. Additionally if you are operating in a region that has constant shifts in the ground, an auto-pointing controller may be better suited to your needs.
Business Data/Internet Applications
Determining what level of bandwidth (link speed of service) that you require will be based upon the number of concurrent users of voice and data, the types of applications in use, the service performance expectations of the user community, and your operating budget.
If you have already calculated your bandwidth requirements you can provide that information to NI or be prepared to answer the questions below, which will help us to make a recommendation on the amount of bandwidth you will require:
- Describe the types of applications that you will use at the remote VSAT site. E.g. Email, File Transfers, ERP, Web Access
- Do any of your applications have specific Application Latency requirements in order to operate? (VSAT latency may be 800-1,200 ms)
- How many concurrent data/Internet users would you have on average during normal operating hours?
- What time of the day will the system be used? E.g. for business applications from 7am-6pm and for leisure/morale applications from 6pm-12am.
- Over the next 1 to 3 years what level of growth do you expect in the number of concurrent users?
NI can provide you with telephone service via Voice over IP (VOIP) on your VSAT system. If you require telephone service, you’ll need to provide information on the questions below:
- Number of Telephone Lines/Handsets that you will require?
- Number of concurrent telephone calls you will have, on average?
- Over the next 1 to 3 years what level of growth do you expect in the number of concurrent telephone/VOIP users?
- Do you have existing standards for types of VOIP equipment? E.g. Cisco
- Will you require NI to provide all VOIP/SIP services or do you want the VOIP/SIP traffic routed to your existing VOIP/SIP server at your corporate offices?
- Do you want to restrict telephone calls (outbound) to specific countries?
- Do you want PIN based codes for users to access the telephones?
- Do you need portable telephone systems for use around the remote site or fixed telephones in a building/shelter?
Video applications for Satellite News Gathering or video conferencing can consume significant amounts of bandwidth. If any type of streaming video is required you’ll need to provide NI with information on the equipment you’re using, any compression technologies in place, video encoders and the quality of service/frame rate that you require.
You may have an IT department that will provide all your LAN equipment for your remote site or you can procure it through Network Innovations. If you desire remote site monitoring of your equipment, then you will need to use commercial grade routers such as Cisco. Items to consider for your LAN at the remote VSAT site include:
- Will you require wireless access for PCs/SmartPhones at the camp site? What range will the wireless access be required for? E.g. in one building, in multiple buildings, around the entire camp site
- Will you want to hard-wire PCs into a switch or router? If so, how many PC/computer systems?
- For hard-wiring of computers, what length of cable runs will be required?
- If you want to make the remote site a node on your corporate wide area network (WAN), then NI can provide VPN services to integrate the site into your corporate WAN infrastructure. Check with your IT team to see if a VPN will be required for integration or security purposes.
Application Prioritization & Filtering Requirements
Network Innovations can help you maximize your bandwidth through the use of filtering and packet shaping devices. These devices block traffic to specific types of web sites to ensure bandwidth isn’t being utilized for non-business purposes. Packet shaping solutions provide the ability to prioritize applications so that your most important applications take precedence in bandwidth allocation. Your IT department may provide you with these types of solutions for deployment at your remote sites or you can procure solutions through Network Innovations. Consider the following as you define your requirements:
- Do you want to filter the use of your VSAT bandwidth to restrict types of websites that cannot be visited? E.g. adult, streaming video, etc.
- Do you want packet shaping to prioritize business applications to maximize the use of your bandwidth?
- Do you want to employ Access Code controls to limit groups or individual users by time, megabytes, or website white/black listing?
Crew/Morale Calling Requirements
Most remote camps recognize the need to provide communications for their staff for non-business purposes. NI can provide you with a variety of options depending upon how you want to manage non-business use of the VSAT communications. One option is to have separate VSAT systems for business and morale/crew usage, thus the non-business usage never impacts the business applications as it is on a separate system. Other options are to use packet shaping to prioritize business over non-business usage. Beyond this, we can provide PIN based usage which restricts and limits usage by users. If crew/morale calling is one of your requirements, then items to consider include:
- Do you want separate VSAT systems for business and non-business usage?
- Do you want PIN based control of non-business usage by user?
- Do you want to charge back VSAT usage to employees for non-business related usage?
- Do you want to filter content and website access for non-business purposes?
- How many concurrent users will you have for non-business usage?
- Will non-business usage be evenings and weekends or around the clock?
- Over the next 1-3 years what growth in non-business usage do you expect in terms of number of users?
- What type/model of devices (PLCs/RTUs) are you utilizing at the remote site?
- Do you require serial to IP conversion for your devices?
- What is the polling/reporting frequency and what are the sizes in bytes of each poll/report?
- What protocol do your PLC/RTUs utilize? E.g. Modbus
- Are the devices to be monitored in close proximity, thus allowing the option of a single satellite uplink for multiple devices, or is a dedicated satcom unit required for each device?
Contract Term Length
VSAT contracts can be occasional use, month to month, annual or multi-year terms. In many cases NI can also offer seasonal usage plans if your operations are only in effect certain months of the year. Longer term commitments will result in lower monthly fees.
Installation & Support Requirements
Network Innovations can provide technical resources for installations and we provide 7×24 telephone support. Successful implementations require a level of self-reliance at the remote site. If you have an on-site IT person, then they are the likely candidate. Otherwise, whomever you designate as the primary on-site contact for NI to work with, that person should spend time with the NI installation team to learn the basics of the installation in the event that a simply component swap is required.
Network Innovations can provide remote site monitoring of your VSAT router, and provided we have access to your main LAN router, we can monitor a variety of performance and availability parameters remotely, to help maximize the reliability of your VSAT system. You should, however, plan to purchase some basic spares so that in the event of a hardware failure, you’ll be able to swap components and get the service back on line in a timely manner.
NI also provides ‘out of band’ management options, whereby we implement a secondary technology, such as BGAN and utilize that as a secondary link or backdoor so that we can remotely access your VSAT equipment to do detailed troubleshooting.