Post Office Telecommunications
Post Office Telecommunications was set up as a separate department of the UK Post Office, in October 1969. The Post Office Act of that year was passed to provide for greater efficiency in post and telephone services. By law, the Post Office had the exclusive right to operate the UK national telecom network, limited ability to license other providers' services and equipment; the 1970s was a period of great expansion for the Post Office. Most exchanges were modernised and expanded, many services, such as STD and international dialling were extended. By the early 1970s, subscribers in most cities could dial direct to Western Europe, the US, Canada; the System X digital switching platform was developed, the first digital exchanges began to be installed. The Post Office procured their own fleet of vans, based on the Commer FC model. However, progress came at a price. Investment was stifled by public spending limits, long waiting lists for telephone lines developed, sometimes for years. In 1979 the Conservatives decided that telecommunications should be separated from the Post Office.
By 1981, the British Telecommunications Act was passed and the service became British Telecom in October that year. Records of the Post Office Corporation 1969-1981 and its predecessors are Public Records, are held by BT Archives. BT Archives EPSS Packet Switch Stream UK telephone area codes BT Archives BT Archives online catalogue
Mitel Networks Corporation is a telecommunications company providing unified communications solutions for business. The company produced TDM PBX systems and applications, but after a change in ownership in 2001, it now focuses entirely on Voice-over-IP products. Mitel is headquartered in Ottawa, Canada, with offices and resellers worldwide. On April 24, 2018, the company announced it would be bought by an investor group led by Searchlight Capital Partners. Michael Cowpland and Terry Matthews founded Mitel in 1973. Conventionally, its name is regarded as a combination of the founders’ first names and their first product – "MIke and TErry Lawnmowers". Cowpland is quoted as stating that it stands for "MIke and Terry ELectronics", whereas Matthews confirmed the lawnmower acronym during an interview on BBC Radio 4's The Bottom Line in May 2011; the pair formed the corporation with the blessing of their employer, Bell Northern Research, in order to protect their intellectual property rights of tone to pulse converter design from their employer, who otherwise would have legal ownership rights.
Their first shipment of three lawnmowers was lost in shipping, so they adjusted to produce a telephony tone receiver product. Cowpland has stated that the lawnmowers were not suited to Canadian lawns. Following the success of the tone receiver, the founders extended their interest in the telecommunications industry. Early on, the pair realized the significance of the then-new microprocessor and software technology to the design of telecom switches. In 1975, they introduced the SX200 PBX; the company grew at a rate of over 100% per year for several years. They reached the $100 million annual revenue mark by 1981. In 1976, the company expanded into the semiconductor field with the acquisition of Siltex, a bankrupt ISO-CMOS foundry in Bromont, Quebec; this evolved into a semiconductor division that specialized in mixed signal and thick film hybrid devices. The next major product was a large digital PBX called the SX2000; this was an early attempt to integrate the data functions of office systems. It was conceived as moving beyond the PBX to become an Office Controller, which would handle both voice and data applications within an organization.
In 1985, due to a financial crisis in the company, the board of directors created enough new shares to sell a controlling interest to British Telecom. British Telecom left the equipment business a few years and sold its controlling interest in Mitel to an investment company called Schroder Ventures. Schroeder Ventures installed new management. In the meantime, Mitel continued to diversify its product line, introducing the successful SUPERSET line of phone terminals, the GX5000 Central Office, the SMART-1 call controller, among others. Additionally, Mitel marketed a line of telecom-focussed semiconductor products. In 2001, Matthews paid $230 million USD to acquire the communications network division of Mitel, along with the Mitel trademark, it began a new chapter, under the name Mitel Networks, by developing a family of PBXs based on Internet standards for Voice over IP. The original company retained the semiconductor division, it was renamed Zarlink Semiconductor to reflect its interest in networking.
Mitel Knowledge Corporation controlled by Matthews, was incorporated in 2001. Numerous patents were transferred to the company, it evolved into MKC Networks, which made a family of SIP-based IP PBX systems. An additional split took place in 2002, when the manufacturing arm was spun off out of Mitel Networks to become a contract manufacturer called BreconRidge. With these developments, the original Mitel Corporation was split into three companies: Zarlink, Mitel Networks, BreconRidge. On May 10, 2006, the new company announced its intention to launch an Initial public offering. No detailed information was released, but the press indicated that the company hoped to raise $150 million. In April 2007, Mitel announced an agreement with Inter-Tel to purchase that company; this purchase would amount to a merger of equals, with the merged company being twice the size of the original Mitel. This acquisition was completed in August 2007. Management had announced; as a result of the merger, Mitel withdrew from the IPO registration process.
"Mitel Knowledge" and Mitel Networks were and are controlled by Terry Matthews. On April 22, 2010, Mitel became a public company, listed on Nasdaq with the symbol MITL, its initial offering stood at $14 per share. Within a year, the stock price had dropped to $5.50 and was described by CNBC's Jim Cramer as one of the worst IPOs of the year. Cramer blamed excessively optimistic pricing, excessive debt and the fear that company insiders would sell, dropping the stock value. During the company's Q1 conference call, Don Smith announced his retirement from the company once the board of directors is able to find a suitable replacement. Smith said. In June 2013, Mitel announced the completion of acquisition of one of its key suppliers, prairieFyre Software Inc. a held global provider of contact center, business analytics, workforce optimization software and services. The net cash cost to Mitel for the acquisition of prairieFyre is $20 million. PrairieFyre is an original equipment manufacturer that has supplied Mitel with its existing contact center solution.
Link Access Procedure, Balanced implements the data link layer as defined in the X.25 protocol suite. LAPB is a bit-oriented protocol derived from HDLC that ensures that frames are error free and in the correct sequence. LAPB is specified in ITU-T Recommendation X.25 and ISO/IEC 7776. It implements the connection-mode data link service in the OSI Reference Model as defined by ITU-T Recommendation X.222. LAPB is used to manage communication and packet framing between data terminal equipment and the data circuit-terminating equipment devices in the X.25 protocol stack. LAPB is HDLC in Asynchronous Balanced Mode. LAPB sessions can be established by either the DTE or DCE; the station initiating the call is determined to be the primary, the responding station is the secondary. I-Frames: Carries upper-layer information and some control information. I-frame functions include sequencing, flow control, error detection and recovery. I-frames carry receive sequence numbers. S-Frames: Carries control information.
S-frame functions include requesting and suspending transmissions, reporting on status, acknowledging the receipt of I-frames. S-frames carry only receive sequence numbers. U-Frames: carries control information. U-frame functions include link disconnection, as well as error reporting. U-frames carry no sequence numbers Flag – The value of the flag is always 0x7E. In order to ensure that the bit pattern of the frame delimiter flag does not appear in the data field of the frame, a technique known as Bit stuffing is used by both the transmitter and the receiver. Address field – In LAPB, this field has no meaning since the protocol works in a point to point mode and the DTE network address is represented in the layer 3 packets; this byte is therefore put to a different use. 01 identifies frames containing commands from DTE to DCE and responses to these commands from DCE to DTE. 03 is used for frames containing commands from DCE to DTE and for responses from DTE to DCE. Therefore, one side must be configured as a Layer 2 DTE and the other as a Layer 2 DCE.
Control field – it serves to identify the type of the frame. In addition, it includes sequence numbers, control features and error tracking according to the frame type. Modes of operation – LAPB works in the Asynchronous Balanced Mode; this mode is signified by the SABM/SM frame. Each station may initialize, recover from errors, send frames at any time; the DTE and DCE are treated as equals. FCS – The Frame Check Sequence enables a high level of physical error control by allowing the integrity of the transmitted frame data to be checked. Window size – LAPB supports an extended window size where the maximum number of outstanding frames for acknowledgment is raised from 7 to 127 and 32767. LAPB has no master/slave node relationships; the sender uses the Poll bit in command frames to insist on an immediate response. In the response frame this same bit becomes the receivers Final bit; the receiver always turns on the Final bit in its response to a command from the sender with the Poll bit set. The P/F bit is used when either end becomes unsure about proper frame sequencing because of a possible missing acknowledgment, it is necessary to re-establish a point of reference.
It is used to trigger an acknowledgment of outstanding I-frames. The following table shows which addresses are placed into the LAPB frame when issuing commands and responses from DTE to DCE and DCE to DTE using single link operation or multilink operation: ISDN Frame Relay Synchronous Data Link Control Link Access Procedures, D channel http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/x25.htm https://web.archive.org/web/20060408153932/http://www2.rad.com/networks/1994/hdlc/hdlc.htm ITU-T Recommendation X.25 ITU-T Recommendation X.222
Session Initiation Protocol
The Session Initiation Protocol is a signaling protocol used for initiating and terminating real-time sessions that include voice and messaging applications. SIP is used for signaling and controlling multimedia communication sessions in applications of Internet telephony for voice and video calls, in private IP telephone systems, in instant messaging over Internet Protocol networks as well as mobile phone calling over LTE; the protocol defines the specific format of messages exchanged and the sequence of communications for cooperation of the participants. SIP is a text-based protocol, incorporating many elements of the Hypertext Transfer Protocol and the Simple Mail Transfer Protocol. A call established with SIP may consist of multiple media streams, but no separate streams are required for applications, such as text messaging, that exchange data as payload in the SIP message. SIP works in conjunction with several other protocols that carry the session media. Most media type and parameter negotiation and media setup is performed with the Session Description Protocol, carried as payload in SIP messages.
SIP is designed to be independent of the underlying transport layer protocol, can be used with the User Datagram Protocol, the Transmission Control Protocol, the Stream Control Transmission Protocol. For secure transmissions of SIP messages over insecure network links, the protocol may be encrypted with Transport Layer Security. For the transmission of media streams the SDP payload carried in SIP messages employs the Real-time Transport Protocol or the Secure Real-time Transport Protocol. SIP was designed by Mark Handley, Henning Schulzrinne, Eve Schooler and Jonathan Rosenberg in 1996; the protocol was standardized as RFC 2543 in 1999. In November 2000, SIP was accepted as a 3GPP signaling protocol and permanent element of the IP Multimedia Subsystem architecture for IP-based streaming multimedia services in cellular networks. In June 2002 the specification was revised in RFC 3261 and various extensions and clarifications have been published since. SIP was designed to provide a signaling and call setup protocol for IP-based communications supporting the call processing functions and features present in the public switched telephone network with a vision of supporting new multimedia applications.
It has been extended for video conferencing, streaming media distribution, instant messaging, presence information, file transfer, Internet fax and online games. SIP is distinguished by its proponents for having roots in the Internet community rather than in the telecommunications industry. SIP has been standardized by the IETF, while other protocols, such as H.323, have traditionally been associated with the International Telecommunication Union. SIP is only involved for the signaling operations of a media communication session and is used to set up and terminate voice or video calls. SIP can be used to establish multiparty sessions, it allows modification of existing calls. The modification can involve changing addresses or ports, inviting more participants, adding or deleting media streams. SIP has found applications in messaging applications, such as instant messaging, event subscription and notification. SIP works in conjunction with several other protocols that specify the media format and coding and that carry the media once the call is set up.
For call setup, the body of a SIP message contains a Session Description Protocol data unit, which specifies the media format and media communication protocol. Voice and video media streams are carried between the terminals using the Real-time Transport Protocol or Secure Real-time Transport Protocol; every resource of a SIP network, such as user agents, call routers, voicemail boxes, are identified by a Uniform Resource Identifier. The syntax of the URI follows the general standard syntax used in Web services and e-mail; the URI scheme used for SIP is sip and a typical SIP URI has the form sip:username@domainname or sip:username@hostport, where domainname requires DNS SRV records to locate the servers for SIP domain while hostport can be an IP address or a qualified domain name of the host and port. If secure transmission is required, the scheme sips is used. SIP employs design elements similar to the HTTP request/response transaction model; each transaction consists of a client request that invokes a particular method or function on the server and at least one response.
SIP reuses most of the header fields, encoding rules and status codes of HTTP, providing a readable text-based format. SIP can be carried by several transport layer protocols including Transmission Control Protocol, User Datagram Protocol, Stream Control Transmission Protocol. SIP clients use TCP or UDP on port numbers 5060 or 5061 for SIP traffic to servers and other endpoints. Port 5060 is used for non-encrypted signaling traffic whereas port 5061 is used for traffic encrypted with Transport Layer Security. SIP-based telephony networks implement call processing features of Signaling System 7, for which special SIP protocol extensions exist, although the two protocols themselves are different. SS7 is a centralized protocol, characterized by a complex central network architecture and dumb endpoints. SIP is a client-server protocol of equipotent peers. SIP features are implemented in the communicating endpoints, while the traditional SS7 architecture is in use only between switching centers; the network elements that use the Session Initiation Protocol for commun
Koninklijke Philips N. V. is a Dutch multinational technology company headquartered in Amsterdam, one of the largest electronics companies in the world focused in the area of healthcare and lighting. It was founded in Eindhoven in 1891 by Gerard Philips and his father Frederik, with their first products being light bulbs, it was once one of the largest electronic conglomerates in the world and employs around 74,000 people across 100 countries. The company gained its royal honorary title in 1998 and dropped the "Electronics" in its name in 2013. Philips is organized into two main divisions: Philips Consumer Health and Well-being and Philips Professional Healthcare; the lighting division was spun off as a separate company, Signify N. V.. The company started making electric shavers in 1939 under the Philishave brand, post-war they developed the Compact Cassette format and co-developed the Compact Disc format with Sony, as well as numerous other technologies; as of 2012, Philips was the largest manufacturer of lighting in the world as measured by applicable revenues.
Philips has a primary listing on the Euronext Amsterdam stock exchange and is a component of the Euro Stoxx 50 stock market index. It has a secondary listing on the New York Stock Exchange. Acquisitions include that of Magnavox, they have had a sports club since 1913 called PSV Eindhoven. The Philips Company was founded by Gerard Philips and his father Frederik Philips. Frederik, a banker based in Zaltbommel, financed the purchase and setup of an empty factory building in Eindhoven, where the company started the production of carbon-filament lamps and other electro-technical products in 1892; this first factory is used as a museum. In 1895, after a difficult first few years and near bankruptcy, the Philipses brought in Anton, Gerard's younger brother by sixteen years. Though he had earned a degree in engineering, Anton started work as a sales representative. With Anton's arrival, the family business began to expand resulting in the founding of Philips Metaalgloeilampfabriek N. V. in Eindhoven in 1908, followed in 1912, by the foundation of Philips Gloeilampenfabrieken N.
V.. After Gerard and Anton Philips changed their family business by founding the Philips corporation, they laid the foundations for the electronics multinational. In the 1920s, the company started to manufacture other products, such as vacuum tubes. In 1939, they introduced the Philishave; the "Chapel" is a radio with built-in loudspeaker, designed during the early 1930s. On 11 March 1927, Philips went on the air with shortwave radio station PCJJ, joined in 1929 by sister station PHOHI. PHOHI broadcast in Dutch to the Dutch East Indies while PCJJ broadcast in English and German to the rest of the world; the international program on Sundays commenced in 1928, with host Eddie Startz hosting the Happy Station show, which became the world's longest-running shortwave program. Broadcasts from the Netherlands were interrupted by the German invasion in May 1940; the Germans commandeered the transmitters in Huizen to use for pro-Nazi broadcasts, some originating from Germany, others concerts from Dutch broadcasters under German control.
Philips Radio was absorbed shortly after liberation when its two shortwave stations were nationalised in 1947 and renamed Radio Netherlands Worldwide, the Dutch International Service. Some PCJ programs, such as Happy Station, continued on the new station. Philips was instrumental in the revival of the Stirling engine when, in the early 1930s, the management decided that offering a low-power portable generator would assist in expanding sales of its radios into parts of the world where mains electricity was unavailable and the supply of batteries uncertain. Engineers at the company's research lab carried out a systematic comparison of various power sources and determined that the forgotten Stirling engine would be most suitable, citing its quiet operation and ability to run on a variety of heat sources, they were aware that, unlike steam and internal combustion engines no serious development work had been carried out on the Stirling engine for many years and asserted that modern materials and know-how should enable great improvements.
Encouraged by their first experimental engine, which produced 16 W of shaft power from a bore and stroke of 30 mm × 25 mm, various development models were produced in a program which continued throughout World War II. By the late 1940s, the'Type 10' was ready to be handed over to Philips's subsidiary Johan de Witt in Dordrecht to be produced and incorporated into a generator set as planned; the result, rated at 180/200 W electrical output from a bore and stroke of 55 mm × 27 mm, was designated MP1002CA. Production of an initial batch of 250 began in 1951, but it became clear that they could not be made at a competitive price, besides with the advent of transistor radios with their much lower power requirements meant that the original rationale for the set was disappearing. 150 of these sets were produced. In parallel with the generator set, Philips developed experimental Stirling engines for a wide variety of applic
Ericsson is a Swedish multinational networking and telecommunications company headquartered in Stockholm. The company offers services and infrastructure in information and communications technology for telecommunications operators, traditional telecommunications and Internet Protocol networking equipment and fixed broadband and business support services, cable television, IPTV, video systems, an extensive services operation. Ericsson had 35% market share in the 2G/3G/4G mobile network infrastructure market in 2012; the company was founded in 1876 by Lars Magnus Ericsson. The company operates in around 180 countries. Ericsson holds over 42,000 granted patents as of December 2016, including many in wireless communications. Lars Magnus Ericsson began his association with telephones in his youth as an instrument maker, he worked for a firm. In 1876, at the age of 30, he started a telegraph repair shop with help from his friend Carl Johan Andersson in central Stockholm and repaired foreign-made telephones.
In 1878 Ericsson began selling his own telephone equipment. His telephones were not technically innovative. In 1878 he made an agreement to supply telephones and switchboards to Sweden's first telecommunications operating company, Stockholms Allmänna Telefonaktiebolag. In 1878, local telephone importer Numa Peterson hired Ericsson to adjust some telephones from the Bell Telephone Company, he analyzed the technology. He was familiar with Bell and Siemens Halske telephones through his firm's repair work for Telegrafverket and Swedish State Railways, he improved these designs to produce a higher-quality instrument to be used by new telephone companies such as Rikstelefon to provide cheaper service than the Bell Group. Ericsson had no patent or royalty problems because Bell had not patented their inventions in Scandinavia, his training as an instrument maker was reflected in the standard of finish and the ornate design of Ericsson telephones of this period. At the end of the year he started to manufacture telephones much like those of Siemens.
Ericsson became a major supplier of telephone equipment to Scandinavia. Its factory could not keep up with demand. Much of its raw materials were imported. Much of the walnut wood used for cabinets was imported from the United States. Stockholm's telephone network expanded that year and the company reformed into a telephone manufacturer; when Bell bought the biggest telephone network in Stockholm, it only allowed its own telephones to be used with it. Ericsson's equipment was sold to free telephone associations in the Swedish countryside and in other Nordic countries; the prices of Bell equipment and services led Henrik Tore Cedergren to form an independent telephone company called Stockholms Allmänna Telefonaktiebolag in 1883. As Bell would not deliver equipment to competitors, he formed a pact with Ericsson to supply the equipment for his new telephone network. In 1918 the companies were merged into Allmänna Telefonaktiebolaget LM Ericsson. In 1884, a multiple-switchboard manual telephone exchange was copied from a design by C. E. Scribner at Western Electric.
This was legal because the device was not patented in Sweden, although in the United States it had held patent 529421 since 1879. A single switchboard could handle up to 10,000 lines; the following year, LM Ericsson and Cedergren toured the United States, visiting several telephone exchange stations to gather "inspiration". They found U. S. switchboard designs were more advanced but Ericsson telephones were equal to others. In 1884, a technician named Anton Avén at Stockholms Allmänna Telefonaktiebolag combined the earpiece and the mouthpiece of a standard telephone into a handset, it was used by operators in the exchanges where operators needed to have one hand free when talking to customers. Ericsson picked up this invention and incorporated it into Ericsson products, beginning with a telephone named The Dachshund; as production grew in the late 1890s, the Swedish market seemed to be reaching saturation, Ericsson expanded into foreign markets through a number of agents. The UK and Russia were early markets, where factories were established improve the chances of gaining local contracts and to augment the output of the Swedish factory.
In the UK, the National Telephone Company was a major customer. The Nordic countries were Ericsson customers. Other countries and colonies were exposed to Ericsson products through the influence of their parent countries; these included Australia and New Zealand, which by the late 1890s were Ericsson's largest non-European markets. Mass production techniques now established. Despite their successes elsewhere, Ericsson did not make significant sales into the United States; the Bell Group and Automatic Electric dominated the market. Ericsson sold its U. S. assets. Sales in Mexico led to inroads into South American countries. South Africa and China were generating significant sales. With his company now multinational, Lars Ericsson stepped down from the company in 1901. Ericsson ignored the growth of automatic telephony in the United States and concentrated
Mercury Communications was a national telephone company in the United Kingdom, formed in 1981 as a subsidiary of Cable & Wireless, to challenge the then-monopoly of British Telecom. Mercury was the first competitor to BT, although it proved only moderately successful at challenging their dominance, it was to set the path for new communication companies to attempt the same. In 1997, Mercury ceased to exist as a brand with its amalgamation into the operations of Cable & Wireless Communications, exited from the telecommunications business by 1999; the history of telecommunications in United Kingdom starts in 1879, with the establishment of its first telephone exchange in London by The Telephone Company Ltd. On 10 March 1881, National Telephone Company – a British telephone company – was formed, which brought together smaller local telephone companies. In 1898, to break the near monopoly held by NTC, the Postmaster General's office, in charge of licensing new telephone companies issued thirteen new licences.
But by 1911, five of the remaining six competitors were taken over by either the General Post Office or NTC. Under the Telephone Transfer Act 1911, NTC was taken over by the GPO in 1912, created a state-run monopoly that would run nearly all telecommunication assets in the UK for the next seventy years. During the 1920s, there was an increasing competition from companies using radio communications such as Marconi's Wireless Telegraph Company. In 1928, it was decided that all telecommunication assets outside of the UK, within the British Empire the telegraph companies, should be merged into one operating company; the merged entity was known as the'Imperial and International Communications Ltd', in 1934 as Cable & Wireless Limited. Following the Labour Party's victory in the 1945 general elections, the government announced its intention to nationalise Cable and Wireless, carried out in 1947; the company would remain a government-owned company, continuing to own assets and operating telecommunication services outside the UK.
All assets in the UK were integrated with those of the General Post Office, which operated the UK's domestic telecommunications monopoly. In October 1969, the Post Office replaced the General Post Office. In October 1981, the Post Office was split into two separate public corporations, the Post Office and British Telecommunications. In 1981, the British government under Prime Minister Margaret Thatcher started the process of privatising nearly all state-run monopolies, including British Airways, British Steel Corporation, British Aerospace, British Telecommunications; the act started the privatisation of Cable & Wireless, a state-run offshore telephone company, whose primary business was in Hong Kong. In 1981, Mercury Communications, Ltd. – a consortium of Cable & Wireless and British Petroleum – was founded as an experiment in telecommunications competition with British Telecom. Its first chairperson was Sir Michael Edwardes, known for his success in turning around British Leyland. Mercury Communications was first licensed in 1982.
The same year, Wireless bought out the stake of its partners. In July 1991, Mercury's sister concern, Mercury Personal Communications Network Ltd, was awarded one of the licences to develop build Personal communications network networks in United Kingdom; the other two went to Microtel Communications Ltd, Unitel. PCNs were envisaged to be superior to the then-existent cellular phone technology, giving customers portability to make or take calls in the home or car, in an aeroplane, or while on holiday. In November 1992, Cable & Wireless sold a 20% stake for about GB£480 million to the Canadian company BCEbc, the parent company of Bell Canada, which gave much-needed telecommunications expertise to Mercury. BCEbc owned two cable companies in the UK. One2One was established as the trading name of Mercury Personal Communications, a joint venture partnership owned by Cable & Wireless and US West International, a division of US WEST Media Group. One2One introduced Britain’s first 1800 MHz GSM network in 1993, in competition with the existing UK mobile networks Vodafone and Cellnet.
Mercury forged strategic alliances with 16 UK cable companies, which enabled them to offer both telephone and television services to their customers. By the end of January 1993, over 117,000 telephone lines were supplied to cable operators by Mercury. In October 1996, Mercury was merged with three cable operators in the UK and renamed Cable & Wireless Communications. Following this, the group embarked on a major disposal programme, selling One2One to T-Mobile in 1999 selling its stake in CWC’s consumer operations to NTL in 2000. From 1986 Mercury operated public payphones in the UK, in competition with BT; these proved not to be profitable and this interest was sold in 1995. They were notable for their varied designs. Mercury operated the first GSM 1800 mobile phone service, launched in 1993, as Mercury One2one; the service was first rolled out in the London M25 area, offered free mobile to landline calls at off-peak times and Bank Holidays. Calls could be made free to landlines in the area the mobile was situated in, to adjacent landline exchange codes.
After this plan ceased being sold, SIM cards that were subscribed to the plan continued to provide these free calls, changed hands for large sums of money. Coverage was extended throughout the decade, with most of the UK having serv