InterSKY for Cellular applications

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Shiron Covers Cellular Coverage

� Shiron provides most suitable broadband satellite solution for cellular providers with following advantages:

� Cellular coverage extension without boundaries of distance,

geographic barriers or terrestrial infrastructure

� High performance Broadband IP connectivity

� True protocol transparency

� Unparallel quality of Voice

� “Jitter & Delay Free” solution

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GSM Architecture

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Cellular (GSM) Bridging Options

� Base Station to BSC (A-bis)

• More of these interfaces than any other

• BTS is most likely to be deployed in an area without terrestrial

infrastructure

� BSC to TRAU (Ater) (optional)

� BSC to MSC (A interface)

� MSC to HLR (C interface) – SS7 interface compression with

SIGTRAN – used for back-up

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TRX: A-bis Interface

� TRX: Radio Transceiver

� Each TRX occupies 2 Time Slots on E1/T1

� TRX only carries compressed voice in 16 Kbps slices

� Signaling and data channel: 16 Kbps for each TRX

� Total Bandwidth: 128 Kbps + 16 Kbps = 144 Kbps

TCH

#1

TCH

#7

TCH

#6

TCH

#5

TCH

#4

TCH

#3

TCH

#2

TCH

#8Signalling

16 Kbps 16 Kbps16 Kbps16 Kbps16 Kbps16 Kbps16 Kbps16 Kbps16 Kbps

TRX

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Cellular Transport Over Satellite

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A-bis Compression Devices

� Convert E1 (TRX + signaling) to IP

� Suppression of traffic from unoccupied TCH

� Silence suppression – suppressing silence greatly reduces bandwidth,

however quantity effects user experience

� Signaling – drop empty signaling frames. Sending only actual

signaling messages reduces capacity by 80%-90%

� No trans-coding: although there are more efficient codecs than used

by GSM systems, the is not converted (trans-coded) for greater

compression

� Increases delay

� Decreases audio quality

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GSM 8TRX Bandwidth Consumption

Graph shows the bandwidth fluctuation for an 8TRX BTS over time.

Although the average is under 600 Kbps, the peak channel capacity

reaches 960 Kbps.

InterSKY Bandwidth on Demand follows the actual bandwidth usage

0

2 0 0

4 0 0

6 0 0

8 0 0

1 0 0 0

1 2 0 01 : 19

: 15

1 : 19

: 25

1 : 19

: 28

1 : 19

: 38

1 : 19

: 52

1 : 20

: 04

1 : 20

: 10

1 : 20

: 20

1 : 20

: 23

1 : 20

: 33

1 : 20

: 54

1 : 21

: 16

1 : 21

: 26

1 : 21

: 33

1 : 22

: 17

S e r ie s 1

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Example TRX Bandwidth Savings

� 2xTCH with no conversation – saves 32 Kbps

� Silence Suppression in 3xTCH saves 3x16x0.8 = 38.4

� Signaling as 20% of channel size saves 0.8x16 = 12.8

� Actual Data Rate: 144 – (2x16) - .8(3x16) – (.8x16) = 60 Kbps

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GSM Bandwidth Savings with InterSKY

Bandwidth reduction with InterSKY is built upon:

� Bandwidth is reduced with GSM A-bis compression device. This

saves ~50% or more of bandwidth

� Shiron InterSKY™ with Bandwidth on Demand (BOD) +

Compression: saves at least another 30% due to fluctuations over time.

� InterSKY™ greater savings if sites are placed in different regions

(highway, industrial, residential) due to higher sharing of capacity

� Shiron can also be used as emergency back-up and activated on

demand