broadband access solutions via satellite sergey eleferov russian satellite communications company...

Broadband Access Solutions via

Satellite

Sergey Eleferov

Russian Satellite Communications Company Satellite Communications Centre “DUBNA”

[email protected]

Broadband Access Solutions via satellite 2

Data Network Access via Satellite

ProviderNetwork

VSAT

Satellite

Subscriber

ProviderEquipment

RouterWorkstation

n x 64 kbpsSatellite channel

•Fixed data speed

•Payments for data speed (not for traffic)

•Relatively expensive VSAT terminal


Hybrid Networks

•Internet traffic multiplexed within DVB-S carrier

•Slow terrestrial link used to request data


DVB RCS Standard• DVB (Digital Video Broadcasting) Return Channel via Satellite (DVB-

RCS) forms the specification for the provision of the interaction channel for satellite interactive networks with fixed return channel satellite terminals (RCST).

• DVB-RCS networks build the platform for high-speed networks supporting all kinds of broadband services running on the Internet.

• DVB-RCS allows for cost efficient broadband satellite transmit and receive links.

• DVB-RCS systems are scalable. A simple, single-gateway DVB-RCS system might serve up to thousands of users, whilst a distributed gateway architecture DVB-RCS system might provide integrated services to several hundred thousand users.

• DVB-RCS may well become a global satellite standard.


DVB RCS Network

Internet

IPNetwork

Satellite

DVB-RCSTerminal

DVB-RCSTerminal

DVB-RCSTerminal

DVB-RCSHUB

StationEthernet

Ethernet

Ethernet

Hub


Satellite Transponder Usage

• Outbound (from HUB to VSAT)One DVB-S Carrier

• Inbound (from VSAT to HUB)FTDMA technique

frequency

Transponder BW (36 МНz)

Pow

er d

ensi

ty

Power spectrum

frequency

Transponder BW (36 МНz)

Pow

er d

ensi

ty Power spectrum

Transponder Amplitude Response

-16

-14

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-8

-6

-4

-2

0

-20 -18 -16 -14 -12 -10 -8 -6 -4 -2 0

-IBO (dB)

-OB

O (

dB

)

Non Linear

Region

Linear

Region

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31

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25 14

25

RA

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RA


Gilat SkyStar 360E NetworkA Skystar 360E network consists of the following components:

• A master earth station and control facility, the Hub

• A number of VSATs, located at the customer's remote sites

• А satellite channels, which provide the transmission medium interconnecting the hub and VSATs


Satellite Access

Skystar 360E uses a combination of satellite access methods for inbound and outbound transmission

• Outbound channel - DVB-S

• Inbound channel architecture is based on a two-dimensional (time and frequency) access scheme (FTDMA). The bandwidth is divided into frequency slots. The time domain is divided into time slots. Remote terminals burst in randomly selected frequency channels at each transmission


Satellite Access (cont)

• Random Access (RA) Mode • Dedicated Access (DA) Mode

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34

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34


Protocol Support

• Skystar 360E supports TCP/IP over Ethernet protocols allowing connectivity for a range of customer devices.

• The Skystar 360E implements an internal router. IP router functions provide the hub with the capability to record device addresses connected to the remote sites. This capability minimizes overhead control messages over the satellite, thereby maximizing data throughput.

• In addition to the IP router functionality, a "TCP Accelerator" is available. Unlike other VSAT or land-based routers, this feature is optimized to provide such capabilities as Internetworking TCP/IP devices. In addition, it maximizes TCP throughput by eliminating control messages over the satellite link


Satellite Resource Optimization

The key to successful IP networking over satellite links is effective management of the overhead traffic, so that it does not delay application message packets. Being an intelligent network, Skystar 360E maintains information internally on attached devices and updates tables maintained in the routing software of the HPS and VSATs. This instant access to the remote device status tables enables the Skystar 360E routers to locally reject messages intended for inactive devices at a remote site.

Satellite resources are optimized in the following manner:

Reducing ARP and RIP Messages

Optimization of Packet Fragmentation

Network Congestion Monitoring


TCP Accelerator

SYNC

ACK

TCP1

TCP2

TCP3

TCP4

ACK

FIN

ACK ACK

SYNC (Source IP-Add, Port, Dest1, PA-Add, Port, Socket)

ACK (Socket)

ACK

ACK1

ACK2

ACK3

ACK4

TCP Session Without Accelerator

SYNC

ACK

TCP1

TCP2

TCP3

TCP4

ACK

FIN

ACK ACK

SYNC (Source IP-Add, Port, Dest1, PA-Add, Port, Socket)

ACK (Socket)

ACK3

ACK3

TCP Session With Accelerator


HTTP Traffic Acceleration over Satellite

HTTP Traffic Without IPA

HTTP GET Get Request (Base Page)

Reply (Base page)

Browser SBL Client w/o IPA SBL Server

Internet Server

Reply (Object1)

Reply (Object1) GET (Object2)

Reply (Object2)

GET Object1

GET (Object 3)

Reply (Object3)


Reply (Base page)

Browser SBL Client w/o IPA SBL Server

Internet Server

Reply (Object1)

Reply (Object1) GET (Object2)

Reply (Object2)

GET Object1

GET (Object 3)

Reply (Object3)

HTTP Traffic With IPA


Reply (Base page)

Browser IPA Client IPA Server Internet Server

GET (Object 1))

Push (Object1,2,3)

GET (Object 2) GET (Object 3)

GET (Object1) Reply (Object1)


GET (Object 3) Reply (Object 3)


Reply (Base page)

Browser IPA Client IPA Server Internet Server

GET (Object 1))

Push (Object1,2,3)

GET (Object 2) GET (Object 3)



GET (Object 3) Reply (Object 3)


Broadcast options

• The Skystar 360E network can be used to support different types of services:

• Data broadcast for applications such as price updates, inventory updates and other bulk-file transfers. This broadcast is an integral part of the Skystar 360E set of features.

• Audio broadcast for applications such as in-store music for retail locations.

• Video broadcast (digital television service) for applications such as training, product announcements and corporate communications.


Quality of Service (QoS) • Based upon the priorities and grade of service, a traffic-shaping algorithm

will monitor and control the available bandwidth on both the inbound and outbound paths. – Outbound QoS : At the hub, QoS can be configured to limit the

maximum amount of traffic that can enter the system. It can also be configured to prioritize applications. A QoS solution can be configured to limit the network resources that are allocated to high bandwidth applications.

– Inbound QoS: At the VSAT there is the capability to prioritize traffic on the resource limited inbound satellite channel. There are certain types of data that cannot be delayed and need priority over ordinary data such as Internet browsing. The Skystar system knows how to automatically identify an application requiring a dedicated channel on the inbound chain and switch from the normal Random Access (RA) mode to the Dedicated Access (DA) mode.


Gilat Skystar 360E VSAT Terminal

• ODU • IDU


Gilat Skystar 360E VSAT Terminal (ODU)


Gilat Skystar 360E VSAT Terminal (IDU)

Parameter Specifications

Number of customer ports 1 (Ethernet) – 10 Mbps

Inbound channel transmission bit rate 38.4 up to 512kbps

Modulator output 950 to 1525 MHz IF

Modulation type MSK

FEC Convolutional and Reed-Solomo n or Turbo

Outbound channel 1

Outbound channel bit rate 2.5 Mbps up to 52.5 Mbps (DVB-S Compliant)

Demodulator input 950 to 1700 MHz IF

Demodulation type QPSK

LAN customer port electrical specification IEEE 802.3 Ethernet

LAN physical interface RJ-45 typical


Coverage Zones

Express A1R Satellite @ 40°0 0

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40 40

50 50

60 60

70 70

80 80-40

-40

-30

-30

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120

6 dB

3 dB

1 dB


Coverage Zones (future)

Express AM2 Satellite @ 80°

broadband access solutions via satellite sergey eleferov russian satellite communications company...

Documents

databroadband access

satellite dvbrcs

satellitedata network

dvbrcs networks

satellite interactive

frequency access scheme

global satellite standard

rcs systems