Iridium Communications Inc.
Iridium Communications: Iridium Satellite LLC is a company, based in McLean, Virginia, United States which operates the Iridium satellite constellation, a system of 66 active satellites used for worldwide voice and data communication from hand-held satellite phones and other transceiver units. The Iridium network is unique in that it covers the whole Earth, including poles, oceans and airways. The company derives its name from the chemical element iridium. The number of satellites projected in the early stages of planning was 77, the atomic number of iridium, evoking the metaphor of 77 electrons orbiting the nucleus; however 95 satellites have been launched so far; the atomic number of americium.
Iridium Communications – OpenPort
OpenPort is a broadband satellite voice and data communications system for maritime vessels. The system is used for crew calling and e-mail services on sea vessels such as merchant fleets, government and navy vessels, fishing fleets and personal yachts. Iridium’s Global Service Program provides shipboard technical support to Iridium OpenPort customers. OpenPort voice services are billed by the minute as with handheld phones, while data services are billed by the megabyte of data transferred (not by the connection time of the session).
Iridium Communications – Services
Calls from Iridium phones can be made to any landline or wireless device in the world and typically cost between $0.75 to $1.50 per minute. Calls made to Iridium phones can be very expensive, costing several dollars per minute. For example, Google Voice charges $4.03USD per minute to directly call an Iridium phone. It is possible to call with charges reversed by first dialing a number in Arizona; the call is charged to the receiver at the standard rate for satellite to landline calls, but the caller only pays for the call to Arizona.
Since Iridium will not sell prepaid cards or even its subscription call service directly, it is hard to obtain the exact price of making a call. There are numerous distributors that will activate Iridium phones and sell pre-paid vouchers and SIM cards.
Voice and data calls
The Iridium system deals with “minutes”, which are subdivided into several much smaller “units”. These minutes are the “basic rate” to landlines and ordinary mobile phones around the world. For a 500-minute annual plan the cost of the “basic rates” fluctuates around US$1.25 per minute, depending on the distributor.
There are also regional plans that offer slightly cheaper rates than the normal, but these minutes can only be used in a specified geographic location (such as Africa, North America, Canada or Alaska).
- Calls to landlines worldwide: 1.00× basic rate
- Calls to other Iridium phones or voice mail: 0.50×
- Sending SMS messages: 0.33×
- Calls to other operator’s satellite phones: 5.00–13.50×
- Data calls: 1.00×
Iridium and other satellite phones may be identifiable to the listener by the “clipping” effect of the data compression and the latency (time delay) due to the electronic equipment used and the distances the signal must travel. The voice codec used is called Advanced Multi-Band Excitation.
Iridium operates at only 2.2 to 3.8 kbit/s, which requires very aggressive voice compression and decompression algorithms. Latency for data connections is around 1800 ms round-trip, using small packets.
Despite the bandwidth limitations, transparent TCP/IP is supported. Iridium claims data rates up to 10 kilobits per second for their “direct Internet” service which utilizes v.42bis compression over a PPP dialup connection to Iridium’s Arizona gateway. Actual data rates remain at 2300 to 2400 bit/s for any compressed data such as a JPG image or ZIP file, but plain text or HTML may transfer “up to” 10 kbit/s. Iridium 9500, 9505 and 9505A phones can be connected to computers using an RS-232 connection, as can the 9522A transceiver module. The 9555 and Extreme phones connect to computers with a standard USB cable, using an internal USB to serial bridge chip and Windows drivers to emulate a serial COM port for compatibility with standard PPP clients.
Prepaid SIM cards are available from a variety of different outlets and sometimes appear on auction sites such as eBay. Their values range from 50 to 5,000 minutes; the 50 minute cards have no validity and the 75 minute vouchers are valid for only a month, but the 5,000 minute cards stay valid for two years. Since Iridium charges quite a bit for merely accessing their network without making calls it is possible to extend the validity of such an account by a month for around US$45. It is also possible to refill such an account without purchasing a new SIM card.
The 500 minute card is the most common one, which remains valid for one year and can usually be bought for US$600 to $750, while the 75 minute card can cost up to US$175 and the 5,000 minute card costs around US$4,000.
There is a basic “Emergency” plan for around US$30 to US$40 per month that offers no minutes at all with calls charged at around US$1.39 per minute, and also numerous plans with included minutes. For the more expensive plans (around US$250 per month), the per-minute price dips slightly below US$1.
Iridium controls the virtual country codes +8816 and +8817, part of the 881 range designated by the ITU for the Global Mobile Satellite System. Each subscriber is given an 8-digit number prefixed by one of these country codes. However many regional telephone service operators have no interconnect agreement with Iridium or other satellite networks and users on these networks need to call reverse charge to a U.S.-based number.
It is also possible to call an Iridium phone by using a US-based gateway number at the Arizona gateway. In this arrangement, a person wishing to call an Iridium phone dials +1-480-768-2500, billed at the standard rates to call the United States from their location, waits for the prompt, enters the +8816 or +8817 number of the Iridium phone they are attempting to reach, and the network then attempts to complete the call. If the Iridium subscriber answers their phone, it will be billed at its standard usage rate, ranging from $0.95 to $1.50 USD per minute, or subtracting minutes from a pool of prepaid minutes assigned to the phone.
Since spring 2007, postpaid Iridium subscribers have an option to associate their Iridium numbers with a direct U.S.-based number (the so-called +1 Access service).
The one-way paging service is still operational, despite the pagers not being in production for many years now. Messages are delivered to pre-selected “MDAs” which cover a certain geographic area. Three of these MDAs may be selected on a web-based portal or updated automatically if the paging service is bound to an Iridium phone. Each country has its own MDA based on its country code; some of the larger countries are divided into several MDAs, while separate MDAs exist for sections of ocean and common aeronautic routes. This service costs around US$70 per month with a limited number of messages allowed, or US$140 for an unlimited number of inbound messages.
Pagers are assigned with telephone numbers in area code 480 and can also be contacted using email, SMS and the web-based interface used to send messages to Iridium phones.
Short burst data
Special modems such as the 9522A, 9601, 9602 and Quake Q9612 can be used for sending and receiving short data bursts, less than 2 kilobytes at a time. This service is often used for asset tracking and remote monitoring. Messages are converted to be delivered in email format or over HTTP to a preconfigured address; the mobile unit does not include a destination address when sending a SBD message. A crude positioning report is also included in each message sent. SBD messages take from 6 to 22 seconds to send or receive. The latest generation of SBD transceiver, the Iridium 9602, can receive up to 270 bytes per SBD data message (defined by Iridium as “mobile terminated SBD”) and can transmit a maximum of 340 bytes per SBD message (defined by Iridium as “mobile originated SBD”). A real-world example of the 9602 chipset in use are the YB Tracker or the owa3x embedded Linux computer.
Iridium Communications. (n.d.). Retrieved June 02, 2016, from https://en.wikipedia.org/wiki/Iridium_Communications