Starlink network bandwidth
In the first application filed by SpaceX with the FCC (Federal Communications Commission), it was indicated that the capacity of one satellite would be 17-23 Gb / s, and was averaged as 20 Gb / s, later one of the messages indicated that each launch 60 - these satellites of the Starlink 1.0 version add about 1 Tbit / s of bandwidth for the network, that is, the bandwidth of one satellite is closer to 16-17 Gb / s. It was also not specified whether this is the total capacity in both directions or only from the Internet to the subscriber ... In any case, it makes no sense to determine the bandwidth of the entire network, since it is unlikely that the entire network can be realized when (70% of the Earth is covered by seas and oceans, in addition, it is very doubtful that the demand in the Sahara and the Himalayas will be the same as in populated areas ).Therefore, it is advisable to talk about the capacity of one satellite and estimate how many subscribers it can serve.
Let's consider separately the capacity of the Starlink satellite in the Ku and Ka bands.
The Ka band (feeder line) here is 4200 MHz in total in 2 polarizations. Taking into account the 64QAM modcodes declared by SpaceX on this line, that is, 6 bit / Hz (the conducted estimate of the radio link budget showed that such spectral efficiency is quite achievable), we can conclude that an estimate of the throughput of 20 Gigabits on the Earth (Internet) -Satellite link is achievable.
However, on the Sputnik-Subscriber line in the Ku band, as we saw earlier, the spectral efficiency when using the current version of the subscriber terminal is 1.5 bit / Hz, that is, if there are only subscriber terminals of type A in the network, then its bandwidth will be only 6 Gbps, three times less than originally expected. Note that when using other versions of it as subscriber terminals, for example, types C and D, with antennas 1.2 or 2.4 meters, the network bandwidth will probably correspond to the declared 17..20 Gbps.
It is also possible to estimate the maximum number of subscribers that one StarLink satellite can serve. If we take the satellite bandwidth of 6 Gbps in the direction from the Internet to the client, then, given the latest data, the average consumption of one US household connected via optics is 281 GB per month, or equivalent to 0.9 Mbit / s with a uniform monthly load, then with a typical load distribution in the networks of an Internet provider, the peak and average monthly load is 1 to 3-4. Thus, the maximum number of subscribers using the current version of the subscriber terminal, which can be served by one satellite, is 1500 ... 2000 subscribers with such traffic consumption. If the volume of traffic per month is limited in the tariff plan, for example, 150 GB,then one satellite will be able to serve twice as many subscribers - 3-4 thousand. The above reasoning is applicable in the case of using multicast satellite frequency resource multiple access (CDMA / TDMA / FDMA) techniques, rather than fixed SCPC channels. More about this in the corresponding section.
Also note that the area of the United States is about 10 million km2, or 2% of the Earth's surface. Accordingly, assuming that due to the "coastal" zones, the number of satellites that can provide service will be 3%, then for the first stage grouping of 1584 satellites over the territory of the United States, no more than 45-48 spacecraft can provide service, that is, the maximum subscriber base for the first stage it will be approximately 150-200 thousand subscribers. With a tariff of $ 80 per month, such a number of subscribers will bring SpaceX an income of $ 150-200 million per year, with a monthly fee of $ 100 per month - $ 200-250 million, which is quite far from the estimates in the 2016 business plan.
StarLink and Rural Digital Opportunity Fund Program
A few words as an introductory explanation.
Providing services in rural areas is unprofitable for telecom operators (infrastructure costs per subscriber are many times higher than in cities. This is an axiom for the whole world. There are only two ways out: either the monopoly of one operator (as, for example, the Post in Russia), which is obliged to provide all residents of the country with a service at an equal price for all (and then the townspeople essentially subsidize the villagers), or if there are many Operators, but the state determines which services must be provided to citizens without fail, they are often called universal, and for their provision the State pays extra from a special fund to Operators who are ready to provide them.
Surcharges come either directly from the budget, or the fund is created at the expense of a quasi-tax, which is paid by all operators in the country. In Russia, it now accounts for 1.2% of Operators' income from services to subscribers and is called the Universal Service Fund.
A similar system exists in the United States, where Operators pay certain amounts to the FCC (Federal Communications Commission), which uses this money to attract Operators to connect to rural areas.
The next stage of such a program, RDOF (Rural Digital Opportunity Fund), began to be discussed in 2019. This is a $ 16 billion grant to improve Internet access for rural areas over the next 10 years. The money is to be distributed at the October 2020 auction among the Operators offering the best service in terms of access speed and traffic volume in different regions of the country, where the access speed is currently below 25 Mbps. Rural Digital Opportunity Fund recipients must offer, on a commercial basis (i.e. for money), to subscribers at least one voice and one broadband service that meets the relevant service requirements for all locations within their won territory within the following time frames:
- 40% of the required number of places in the state by the end of the third year
- and an additional 20% by the end of the fourth and fifth year of receiving grants
To identify the winner, a system for calculating penalty points is proposed, depending on the technical parameters of the Internet access service. There are 4 speed gradations:
Regarding satellite technology, the rules are written strictly against all satellite operators. Penalty points are awarded to each Operator.
Ideal is the proposal of the Operator, which will provide a speed of 1 Gbit: he will have 0 penalty points and a delay of less than 100 milliseconds, he is practically guaranteed a victory and a grant.
The delay requirements are simply "killed" by the existing service of ViaSat and Hughes Network Systems operators working with satellites in geostationary orbit:
They receive 40 penalty points at once, and can only be better than those who work on the ancient ADSL.
SpaceX has been trying to qualify for federal subsidies for rural broadband services since 2019, despite objections from competitors that claim its satellite technology hasn't been tested in practice. In a letter to the FCC, SpaceX says its technology will expand choices for rural subscribers. "Banning SpaceX from participating in an auction, despite the compliance of its service with the technical requirements of the auction, may lead to the fact that subscribers will be limited in their choice and will not receive the best possible service." - wrote David Goldman, director of satellite policy for SpaceX.
The FCC has begun public consultations on SpaceX's proposal to change the rules for allocating funds for this program. An FCC spokesman said the agency expects to receive public comment on its proposal.
"The goal of the Rural Opportunity Fund is to use the money from the Universal Service Fund to provide the fastest internet possible for as many Americans as possible," the statement said.
The published draft version of the auction, proposed by the FCC on February 7, 2020, contained language prohibiting satellite companies from qualifying as a low latency (ping) service, making their bids less attractive than fiber-optic bidders.
SpaceX met with FCC staff on February 18 and 19, 2020, and argued that its non-GSO satellites have low latency, which stems from the basic laws of physics. In a letter sent to the FCC on February 20, SpaceX says its satellite system has demonstrated that it can provide high-speed internet.
The FCC, as a result of SpaceX's activities, has changed its position in a new version of the terms of the Auction approved by the FCC on February 28. The agency has left the possibility that low-Earth orbit satellite services could be categorized as Low-Latency Operators, and has requested public comment on SpaceX's claims.
These changes have sparked strong opposition from existing rural Internet providers, who believe that allocating funds for SpaceX's satellite technology is a risky game, since SpaceX cannot confirm the experience of providing broadband access to subscribers. “We will not let SpaceX speculate with public money ,” said Jonathan Chambers, a former FCC employee and partner at Conexon LLC, which builds fiber-optic networks for rural telecom operators.
According to an article in The Wall Street Journal, the controversy reached Capitol Hill, where congressional aides and lobbyists discussed how to pressure the FCC to keep SpaceX out of the auction. "It would be a political disaster if 'fucking' Elon Musk devours billions of dollars in public money," one of the congressman's aides said in one of his e-mails last week.
"This will be a political disaster if Elon f'ing Musk gobbles up billions of dollars of the public's money,")
A group called NTCA - the Rural Broadband Association and the National Association of Rural Electricians' Cooperatives, whose members sometimes offer internet access along with electricity - said they are asking Congress and the FCC not to accept SpaceX's proposals.
The NTCA has sent emails to Congressmen urging them to contact the FCC and express concerns about satellite constellations in non-GSOs participating in the auction.
"Although this is just a proposal so far, but if it is accepted, it may lead to the fact that the satellite provider (ie SpaceX) can win the entire auction (all its lots) ," wrote the NTCA lobbyist.In an interview, NTCA Senior Vice President Michael Romano stated that SpaceX's proposals could allow satellite companies to bid on any of the auction lots.
As a result of vigorous actions by SpaceX opponents in May 2020, the FCC backed down and introduced new wording for satellite networks in low orbit (paragraphs 106-109 of the RDOF Auction rules) into the rules, published by the FCC on May 19, 2020. Their main content is as follows:
108. , , , , , . (Viasat) , , , . . , , « » — , , « » — , . . , , . , , .
109. , , 100 , , , .
Item 109 is clearly written to SpaceX. Naturally, this angered SpaceX, and the active work of their lobbyists, however, it is difficult to understand if they could have convinced the FCC if Space X had not carried out the launch of the manned Dragon spacecraft with astronauts on board on May 30, 2020, which NASA has been waiting for since 2014. year and which broke Russia's monopoly on the delivery of astronauts to the ISS. Elon Musk met on this occasion with US President Donald Trump and received well-deserved congratulations from him.
Literally 10 days after these events, the Director of the FCC and his deputy Jeffrey Starks discerned the vast technological possibilities in the StarLink system, apparently unknown to them. FCC Commissioner Jeffrey Starks said: « -10 . ' - , , , 100 . , .»
FCC Chief Ajit Pai, appointed by Donald Trump
FCC Chairman Ajit Pai has been more cautious. On June 11, 2020, at a press conference, he stated:
«, -, LEO, . : — , . . , . . «t» (. i)(«t's to be crossed»), . .»The final conditions for participation in the RDOF tender looked like this on July 15:
- Demonstrate two years of experience in providing voice, broadband and / or power distribution or transmission services and provide audited financial statements for one year or
- Submit audited financial statements for three years with a short application form and a letter of interest from the relevant bank wishing to open a letter of credit for the indicated amount.
Organizations will also be required to provide detailed technical information to demonstrate that they have the technical qualifications to meet the applicable rate and latency level requirements.As
we can see, SpaceX was able to participate in the auction, which it did by simply submitting financial statements and detailed description of the StarLink system by July 15, 2020.
On October 13, the FCC published a list of companies admitted to the auction itself, Space X, along with ViaSat and Hughes Network Systems, represents satellite operators. At the same time, there is no information what amount of delay the FCC experts attributed to StarLink and, accordingly, with whom it will compete.
It remains to wait for the auction itself (it began on October 29, 2020 and is closed until 4 rounds have taken place) and further developments, its results, the amount of subsidy for one connected house, etc. This process can take 6 to 18 months prior to contracting to allow the FCC to verify that the StarLink network is operational and truly operational.
- Everything about the Starlink Satellite Internet project. Part 1. Birth of the project
- Everything about the Starlink Satellite Internet project. Part 2. Starlink Network
- Everything about the Starlink Satellite Internet project. Part 3. Ground complex
- Everything about the Starlink Satellite Internet project. Part 4. Subscriber terminal
- Everything about the Starlink Satellite Internet project. Part 5. Starlink constellation status and closed beta
- Everything about the Starlink Satellite Internet project. Part 6. Beta testing and service for subscribers