Satellite Broadband Connectivity Plans
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UpStream |
512 kbps |
250 kbps |
500 kbps |
750 kbps |
1 Mbps |
DownStream |
2 Mbps |
1 Mbps |
1 Mbps |
1 Mbps |
1 Mbps |
Shared Network Plan (1)
Full Time Monthly |
$ 350 |
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CIR/CRA Dedicated (2)
VoIP Circuit *
(monthly per phone) |
$ 45 |
Streaming Video
On-Demand Day Rate |
$ 132 |
$ 250 |
$ 375 |
$ 500 |
Definitions:
Shared Network: A plan where a relative number of users simultaneously share a network channel.
CIR: Committed Information Rate
CRA: Committed Rate Assignment
CIR (Committed Information Rate) and CRA (Committed Rate Assignment) are terms referring to dedicated satellite bandwidth required by the service provider in order to operate high bandwidth applications such as video streaming over the satellite.
CIR / CRA Services:
Commercial level service providers offer CIR/CRA packages; most consumer level operators do not.
The pricing for these services will be significantly higher than shared ratio services. Most VoIP services require CIR/CRA services to ensure robust telephony circuits. A single VoIP call can consume between 40kbps up to 90kbps.
Actual Measured Speeds:
Service providers offer rate plans that have an uplink (UpStream) or return data rate, and a downlink
(DownStream) or forward data rate; and are referred to as “a service of 512 X 2000”. The larger number
is the forward (DownStream) channel, which is your downlink as a user; and the larger number is the
return (UpStream) channel, which is the uplink as a user. An important point to understand is that the
speeds include IP overhead.
Every internet system whether its satellite or terrestrial uses IP protocols that require a certain amount of bandwidth to process the IP traffic (called overhead); which is typically 20%. Actual measured payload speeds will be approximately 20% less than the published rates of the plan. Actual speeds can be
measured by running a speed test from a PC over the satellite link.
Contention Ratio and/or Over Subscription:
The terms Contention Ratio and Over Subscription refer to the number of users that can simultaneously share a network channel within a service provider’s shared network plans.
A Shared Network Plan within a satellite service provider’s Internet services operates a system that
utilizes TDMA (Time Division Multiple Access). The TDMA system is controlled by a central hub location,
which addresses the remote units in the field at the appropriate time to transmit the data to the hub.
TDMA allows for large number of remote units to share the same channel of bandwidth that improves the
overall efficiency of the system. The transmissions from the remote units are sequenced at a very high
rate, many times per second, which makes the service appear to be continuous.
In a shared network plan, as more units are added to the system, the slower the service will be. A
reputable commercial service provider will typically limit their contention ratio to never exceed 20:1 or 20
terminals per segment of bandwidth. Service providers that offer lower grade services will over subscribe
or raise their contention ratios as high as 40, 80, 120:1 or more. Consumer type services typically run in
the 120:1 or higher range.
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