Internet access via satellite

Internet via satellite is satellite broadband Internet access . Geostationary satellites are often used for this . However, there are also satellite constellations in low and medium earth orbit (LEO and MEO) that can be used for Internet access, for example O3b . With OneWeb and Starlink , two new large constellations of several hundred and thousand satellites respectively have been under construction since 2019.

Satellite system for internet access

variants

Basically, a distinction must be made between two types of satellite connection.

2-way satellite connection

With this form of connection, the outward and return channels (downstream and upstream) are established via a satellite (since 2013).

In the downstream , transmission rates between 64 kbit / s and 150 Mbit / s are available, depending on the provider , and different transmission rates in individual cases to be negotiated. The transmission rate of the upstream is between 64 kbit / s and 20 Mbit / s depending on the target group (end users and professional users). Technically, however, much higher transmission rates are possible. The Belgian satellite technology company Newtec reported in mid-June 2012 that it was using a 72 MHz transponder on a Eutelsat satellite to achieve speeds of over 500 Mbit / s.

1-way satellite connection

An asymmetrical connection, first used more than 15 years ago, in which only the downstream was routed via a satellite, but the upstream was via terrestrial connections. This technical solution was still used by tens of thousands of users in Europe until around 2013. At the time, downstream transmission rates between 256 kbit / s and 36000 kbit / s were available to the user, depending on the provider. The reception of the satellite signals can also take place with a commercially available DVB-S card , provided that the modulation is supported and compatible software is available.

The data transmission rate of the return channel was based on the technology used. Modem connections were mostly used via POTS or ISDN connections, which provided upstream rates of up to 128 kbit / s . For mobile applications, GPRS , UMTS or GSM connections could also be used for the return channel.

For connections with a terrestrial return channel, this was used by some providers in parallel to the satellite link for data transmission in the downstream direction. If this return channel is busy, the other packets flow over the satellite transmission route, which is more expensive for the provider. Conversely, this means: If the terrestrial line is not fully utilized - e.g. B. due to a slow Internet server - all data arrive terrestrially. For providers who did not use this technology, the actual download was exclusively via satellite.

advantages

Satellite internet modem and antenna in use at the Red Cross in South Sudan .

The advantage of satellite connections lies in the combination of the relatively large bandwidth and its wide availability, which is largely independent of location.

The advantage of the pure satellite connection is that it is available completely independently of terrestrial data or telephone lines and no fixed location is required. It is therefore also available for ships and aircraft. The user only has to be in the broadcast area of a suitable satellite or move within it.

Another advantage is that the existing internet connection can also be used for making calls ( VoIP ). This makes a conventional telephone connection superfluous.

disadvantage

Latency and Slow Start

The long distances alone and despite the speed of light of around 300,000 km / s result in z. B. with geostationary satellites from the earth station to the satellite and back to the service user signal transit times of at least 239 ms. In the case of bidirectional communication via the satellite, this route must be overcome twice for the outbound route of inquiries and the return route of a response. Together with other delay factors, latencies between 500 and 700 ms result, which is comparatively significantly worse than z. B. the typical latencies of 150–200 ms for modem dial-up. DSL latencies are of the order of 20 ms. Internet services that use the satellite for there and back are therefore not suitable for video telephony and games or other applications in which high latency times are associated with severe restrictions.

The Transmission Control Protocol (TCP) is not designed for these high latencies. The Round Trip Time (RTT) resulting from these runtimes means that a TCP connection does not increase the data transfer rate significantly after the so-called slow start and so only a few 10 kbit / s could be transferred under unfavorable conditions even with a high theoretical data transfer rate. This problem can be avoided by using the Performance Enhancement Proxy .

Transparency vs. Transfer rate

The requirements for the most effective possible use of the theoretically available data transmission rates and the greatest possible application transparency can usually not be met at the same time. The most effective data transfer rate utilization is offered by the client / server variant with the one-way service . It routes the connection in front of and behind the satellite connection via a proxy server (client and remote proxy). In order to remain application-transparent, a tunnel variant ( VPN / PPTP ) is usually offered for the one-way service .

Data rate limitation

Similar to the use of the Internet via mobile radio, most providers of satellite Internet access also have a fair use policy that can lead to the actually available data rate being throttled.

development

There will be more and more broadband satellite connections in the near future in order to be able to satisfy the increasing demand for data as an additional component in addition to the fiber optic network. While the fiber optic expansion requires a lot of time and high investments, Internet via satellite is largely independent of location and online in a very short time.

providers

providers	Broadcast area	position	product	Connection type	Downstream (max)	Upstream (max)	Downstream (min)	Upstream (min)	Dual play	Triple play
Arabsat				2-way
atrexx	Asia, Africa, Europe, Middle East, USA		2way2sat LinkStar	2-way	2,048 kbit / s	1,024 kbit / s	128 kbit / s	64 kbit / s
Businesscom Networks Limited	Asia, Africa, Europe, Middle East, North America, South America		"IDirect" - VSAT	2-way	8,000 kbit / s	1,000 kbit / s	256 kbit / s	64 kbit / s	No	No
CETel GmbH	Europe			2-way
Comnet	India			2-way
dsl2u	Europe		(= Eusanet 2010)	2-way	3,600 kbit / s				No	Yes
EgyptSat Telecom	Africa			2-way	18,000 kbit / s	4,200 kbit / s
EUTELSAT SA	Europe	9 ° East	tooway	2-way	30,000 kbit / s	6,000 kbit / s			Yes	Yes
EUSA NET GmbH	Europe		SATSPEED / KA-SAT / VSAT	2-way	30,000 kbit / s	6,000 kbit / s			Yes	Yes
Filiago	Europe		SES Broadband AVANTI Eutelsat	2-way	30,000 kbit / s	6,000 kbit / s	10,000 kbit / s	256 kbit / s	Yes	Yes
getinternet GmbH	Europe		Tooway – KA SAT	2-way	22,000 kbit / s	64 kbit / s	64 kbit / s	1,000 kbit / s	No	No
Global star			Sat-Fi	2-way
HughesNet	Alaska, Canada, Puerto Rico, USA			2-way	15,000 kbit / s
Inmarsat			Broadband Global Area Network	2-way	700 kbit / s
IPcopter	Europe		fnp012	2-way	10,000 kbit / s	256 kbit / s
IPSTAR	Asia, Australia		Ultimate "Vol"	2-way	4,000 kbit / s	2,000 kbit / s
iridium	Worldwide		Iridium (-NEXT)	2-way	128 kbit / s (1,400 kbit / s)	128 kbit / s	2.4 kbit / s	2.4 kbit / s	Yes	No
level421	Africa, Europe			2-way
Novostream GmbH	Europe	28.2 ° East / 31.0 ° East	Astra-KA SAT / Avanti	2-way	20,000 - 50,000 kbit / s	2,000 - 4,000 kbit / s	no throttling	no throttling	No	No
ORBITCOM GmbH	Europe		Astra – KA SAT	2-way	20,000 kbit / s	2,000 kbit / s	256 kbit / s	256 kbit / s	No	No
SAT network	Europe			2-way	10,000 kbit / s	4,000 kbit / s			Yes	Yes
Sat Internet Services GmbH	Europe		Tooway – VSAT	2-way	22,000 kbit / s	6,000 kbit / s	k. A.	k. A.	Yes	Yes
Bugle	Europe			2-way
SES Astra	Europe	28.2 ° East	Astra Connect	2-way	25,000 kbit / s	2,000 kbit / s
SkyGate	Europe, Middle East		"Volume"	2-way	4,096 kbit / s	256 kbit / s		Yes	Yes
skyDSL	Europe		skyDSL2 + / KA-SAT / VSAT	2-way	25,000 kbit / s	6,000 kbit / s	6,000 kbit / s	1,000 kbit / s	Yes	Yes
Sosat	Europe		dsDSL power	2-way	22,528 kbit / s	6,144 kbit / s	256	64
Spacenet	North America			2-way
StarDSL	Europe		Tooway	2-way	22,000 kbit / s	6,000 kbit / s
Thuraya	Europe, Africa, Asia, Australia		ThurayaIP	2-way	444 kbit / s	444 kbit / s	16 kbit / s	16 kbit / s	No	No
Vconn / AZ Communication	Philippines		VCONN VSAT	2-way	1,000 kbit / s	512 kbit / s
WildBlue	North America		Liberty "GB"	2-way	25,000 kbit / s	3,000 kbit / s

Web links

IP via Sky Förderverein Internet und Mediendienste e. V.

Individual evidence

↑ Filiago brings Internet via satellite with a return channel , golem.de
↑ And again the broadband desert got a lot smaller. Filiago GmbH & Co KG, August 3, 2012, accessed on January 31, 2015 .
↑ Internet in the countryside from Novostream | High speed internet | No DSL? Accessed November 15, 2018 (German).
↑ ASTRA Connect | Astra. Retrieved November 15, 2018 .
↑ StarDSL is now offering Internet via satellite with a return channel , golem.de
↑ thuraya.com Thuraya IP Price Plans

[1] Filiago brings Internet via satellite with a return channel , golem.de

[2] And again the broadband desert got a lot smaller. Filiago GmbH & Co KG, August 3, 2012, accessed on January 31, 2015 .

[3] Internet in the countryside from Novostream | High speed internet | No DSL? Accessed November 15, 2018 (German).

[4] ASTRA Connect | Astra. Retrieved November 15, 2018 .

[5] StarDSL is now offering Internet via satellite with a return channel , golem.de

[6] thuraya.com Thuraya IP Price Plans