Local number portability
From Wikipedia, the free encyclopedia
 |
This article or section deals primarily with the United States and does not represent a worldwide view of the subject. Please improve this article or discuss the issue on the talk page. |
Local number portability, (LNP) for fixed lines, and full mobile number portability (FMNP), for mobile phone lines, refers to the ability to transfer either an existing fixed-line or mobile telephone number assigned by a local exchange carrier (LEC) and reassign it to another carrier. In most cases, there are limitations to transferability with regards to geography, service area coverage and technology.
In the United States and Canada, mobile number portability is referred to simply as WNP or WLNP (Wireless LNP). Wireless Number Portability is available in some parts of Asia, Australia, and most European countries including Britain; however, this relates to transferability between mobile phone lines only. Canada and the United States are the only two countries in the world that offer full number portability transfers between both fixed lines and mobile phone lines.[1][2]
Most cellular telephone companies will charge for this conversion as a regulatory cost recovery fee.
Contents |
[edit] History
Number portability became popular with the advent of mobile telephones, since in most countries different mobile operators are provided with different area codes and, without portability, changing one's operator would require changing one's number. Some operators, especially incumbent operators with large existing subscriber bases, have argued against portability on the grounds that providing this service incurs considerable overhead, while others argue that it prevents vendor lock-in and allows them to compete fairly on price and service. Due to this conflict of interest, number portability is usually mandated for all operators by telecommunications regulatory authorities. In the US, LNP was mandated by the FCC in 1997 with the First Report and Order on LNP and Number Pooling. The mandate required all carriers in the top 100 msas (metropolitan statistical areas) to be "LNP-capable" and port numbers to any carriers sending a BFR (bonafide request). The ability to keep a number while switching providers is thought to be attractive to consumers. It was also a major point made by CLECs (Competitive Local Exchange Carriers) preventing customers from leaving ILECs (Incumbent Line Exchange Carriers), thus hindering competition.
In the U.S., the Federal Communications Commission (FCC) has mandated this in order to increase competition among providers. As of late November 2003, LNP was required of all landline and wireless common carriers, so long as the number is being ported to the same geographical area or telephone exchange. This latest mandate included carriers outside the top 100 msas that heretofore enjoyed a rural carrier exemption.
[edit] Portability by country
[edit] Australia
In Australia, mobile telephone numbers have been portable between carriers since 2001. Previously, prefixes 04x1, 04x2 and 04x3 referred to Optus customers, 04x4, 04x5 and 04x6 referred to Vodafone numbers, and 04x7, 04x8 and 04x9 referred to Telstra. Portability has been a great asset in allowing freedom of choice of service provider. However many telecommunications companies had special or discount rates for calls between two customers of the same service provider, which although the special rates still existed, it was made difficult for customers to determine which provider the person they were calling was with. Land line phone numbers are tied to a particular physical telephone exchange - as of 2004 there are no plans or demand to change this.
[edit] Canada
In Canada, wireline/competitive local exchange carriers must provide portability. As of March 14, 2007, wireless carriers must provide portability in most of Canada[3].
[edit] Europe
In the European Union, all telephone providers are required to provide number portability under the Universal Services Directive (2002/22/EU).
[edit] United Kingdom
In the United Kingdom, Ofcom directs fixed-line telephone network providers, mobile 'phone providers and broadband service providers to provide number portability under the Porting Authorisation Code rules and Migration Authorisation Code code of practice respectively. As the UK is an EU member country, the Ofcom direction is intended to reflect the requirements of EU Directive 2002/22/EU.
[edit] India
In India, the Telecom Regulatory Authority (TRAI) has plans to implement portability by mid-2006. However this has been stiffly opposed by many private cellular operators who claim that it will prevent growth.
[edit] Japan
In Japan, 番号ポータビリティー制度 (bangō portability seido - commonly referred to as portability or MNP) began on October 24, 2006. Users will be able to change celluar phone carriers without changing their number for a fee of 5000 yen. However, e-mail addresses are subject to change, and music/data downloaded may not be used.
[edit] Singapore
The world's first country to introduce number portability for mobile telephones was Singapore in 1997.
[edit] United States
In the United States, the FCC first mandated LNP among wireline carriers in 1997, as well. The US FCC since has mandated Wireless Local Number Portability starting November 24, 2003 (in metropolitan areas), and allowed operators to charge an additional monthly Long-Term Telephone Number Portability End-Use Charge as compensation. On November 10, 2003, the FCC additionally ruled that number portability applies to landline numbers moving to mobile telephones as well.
[edit] Technical issues
Complexity for number portability can come from many sources. Historically, numbers were assigned to various operators in blocks. The operators, who were often also service providers, then provided these numbers to the subscribers of telephone services. Numbers were also recycled in blocks. With number portability, it is envisioned that the size of these blocks may grow smaller or even to single numbers. Once this occurs the granularity of such operations will represent a greater workload for the telecommunications provider. With phone numbers assigned to various operators in blocks, the system worked quite well in a fixed line environment since everyone was attached to the same infrastructure. The situation becomes somewhat more complex in a wireless environment such as that created by cellular communications.
In number portability the “donor network” provides the number and the “recipient network” accepts the number. The operation of donating a number requires that a number is “snapped out” from a network and “snapped into” the receiving network. If the subscriber ceases to need the number then it is normal that the original donor receives the number back and “snaps back” the number to its network. The situation is slightly more complex if the user leaves the first operator for a second and then subsequently elects to use a third operator. In this case the second operator will return the number to the first and then it is assigned to the third.
In cellular communications the concept of a location registry exists to tie a “mobile station” (such as a cellular phone) to the number. If a number is dialed it is necessary to be able to determine where in the network the mobile station exists. Some mechanism for such forwarding must exist. (For an example of such a system, see the article on the GSM network.)
In the US, there are standards for portability defined by the FCC and the LNPA, as well as NANPA and the ATIS which are agreed upon by all member providers to help make LNP as cost-efficient and expedient as possible while still retaining a healthy level security for all providers and in respect of the highest level of customer service. These rules, first defined in the 1st, 2nd and 3rd Reports and Orders by the FCC (publicly available at fcc.gov), are further detailed by the LNPA in order to ensure any provider can successfully port numbers to any other provider. Neustar provides a national database called the NPAC (National Portability Administration Center) which contains the correct routing information for all ported and pooled numbers in the US and Canada.
Providers use SS7 to route calls throughout the US/Canada network. SS7 accesses databases for various services such as CNAM, LIDB, CLASS and, of course, LNP. Calls to ported numbers are completed when a customer who calls a ported number sends the dialed number to a provider's SSP (Service Switch Point), where it is identified either as a local call or not. If the call is local, the switch has the NPA-NXX in its routing table as portable, so it sends a routing request to the STP (Signal Transfer Point) which accesses a local database that is updated by an LSMS (Local Service Management System) which holds all routing for all ported numbers to which the carrier is responsible for completing calls. If routing information is found, a response is sent to the "query" containing the information necessary to properly route the call. If it is not a local number, the call is passed on to the STP and routed until it gets to a local carrier who will perform the "query" mentioned earlier and route the call accordingly.
The routing information necessary to complete these calls is known as an LRN (Location Routing Number). The LRN is no more than a simple 10-digit telephone number that resides in the switch of the service provider currently providing service for the ported telephone number.
When a provider receives a request to port a telephone number from a new customer, that provider sends an industry-standard LSR (Local Service Request) to the exising (or "old") provider. When the Old Provider receives this request, it sends back FOC (Firm Order Confirmation) and the 5-day max process of porting the number begins. Either provider can initiate the port using a SOA or LSOA (Service Order Activator) which directly edits the NPAC database mentioned before. If the new provider initiates the port, it is called a "pull," and if the old provider initiates, it is a "push." Once the number is pulled or pushed, the new provider must "activate" the number using the LRN of the switch serving the customer. At the point this is completed, the number is ported.
Much of this process is duplicated in intermodal portability (porting between wireline and wireless providers). There are a few technical differences, however, in WLNP-- Especially with concern to the time intervals allowed.
[edit] References
- Canadian Radio-television and Telecommunications Commission - Cellular (Wireless) Telephone Services (Fact Sheet) (March 2006)
- NHK Article (September 2, 2006)(Japanese)
[edit] See also
[edit] External links
- http://wireless.fcc.gov/wlnp/
- http://www.fcc.gov/cgb/consumerfacts/numbport.html
- Canadian Number Portability news & facts.
- CRTC (Canadian) Factsheets (March 2006)
- PCWorld.ca Mobile phone numbers go portable (March 2007)
