Satellite Internet

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Satellite Internet

• High Speed Internet Virtually Anywhere

2
Why Satellite Internet?

• Pros
• Available Virtually Anywhere
• WildBlue available almost anywhere in lower 48
• Must have clear LOS
• Fast (compared to dial-up)
• Up to 1.5 Mbs down
• Up to 256 Kbs up

3
Why Satellite Internet

• Cons
• Relatively Expensive
• Starts at 49.95 per month for 512 Kbs down
• Similar to dial-up plus 2nd line
• Weather Affected
• Weather at customer
• Weather at gateway
• Seldom occurs in SD

4
Why Satellite Internet

• Cons
• Limits On Bandwidth Usage
• Download threshold 7.5, 12, 17 GB in rolling 30
  day period
• Upload threshold 2.3, 3, 5 GB in rolling 30 day
  period

5
Why Satellite Internet

• Cons
• Latency
• Delay caused by 22,300 mi trip to satellite and
  back
• At best about 600 ms
• Interactive gaming may be affected
• VoIP is not supported
• VPNs may be very slow or unusable
• SSL based works better than IP sec based

6
Frequencies

• C-band
• 3.7 to 4.2 GHz
• Original band for communication satellites
• Uses BUDs (Big Ugly Dish)

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The Technology

• Ku-band
• 12 to 18 GHz
• Used for DBS (satellite TV)
• Uses small dish (higher frequency uses smaller
  dish for same gain)

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Frequencies Continued

• Ka-band
• 27-40 GHz
• WildBlue 19,700 to 20,200 GHz for downlinks
• 29,500 to 30,000 GHz for uplinks

9
The Technology

• Spot Beam Technology
• Narrow, focused beams allow reuse of frequencies

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The Technology

• Spot Beam Technology
• Narrow, focused beams allow reuse of frequencies
• Anik F2 uses 31 subscriber beams, and 5 gateway
  beams
• Beams overlap to provide near 100 coverage
• Satellite combines several user links to one
  feeder link

11
Spot Beams
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Spot Beam Usage

• 8 Ranges of Frequencies for Downlink
• Each Spot Beam Uses 1 Range
• Each Modem Uses 1 of 4 Carrier Waves Within that
  Range

13
Satellite Protocols

• TCP/IP from PC to SMCI
• SF-TDMA or MF-TDMA from SMCI to SMTS-NSI
• Single Frequency-Time Division Multiple Access
• Multiple Frequency-Time Division Multiple Access
• Format of Packets is DOCSIS
• Data Over Cable System Interface Specification
• TCP/IP from SMTS-NSI to Gateway Server

14
Installation

• 5 Characteristics to Consider
• Azimuth (direction)
• Elevation
• Polarization
• Skew
• Beam Assignment

15
Installation

• Azimuth
• Can use compass to determine general direction.
• Set elevation, then rotate dish to find signal

16
Installation

• Elevation
• Use Inclinometer on Dish
• Boom Arm angle is about 17 degrees less than
  elevation.

17
Installation

• Polarization
• Left Hand or Right Hand depending On Satellite.
• Tria must have proper polarization

18
Installation

• Skew
• Aligns elliptical dish with GEO arch
• With circular polarity only necessary if signal
  received from more than one satellite or to
  exclude interference
• Debate on whether to skew or not skew
• WildBlue specifies all skew set at 90

19
Installation

• Beam Assignment
• Modem must lock on to correct beam
• 8 possible beam frequency ranges
• Use APA (Antenna Pointing Aid) set to correct
  number to lock on to correct beam

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Beam Assignment
21
Cabling

• Dual Coax Runs from Dish to Modem
• One for Receive, One for Transmit
• Grounding Block is Installed to Ground Dish
  through Coax Outer Conducter

22
Operation

• Modem Lights Indicate Lock on Satellite
• Browser is Set to Use Proxy
• Modem has Acceleration Software.
• Modem acknowledges TCP connections without
  waiting for server to establish connection.
• Saves one round trip for each Web object
• Traffic is Prioritized, ICMP is at Bottom