No. 28.... October 1996
Issued by the Oftel Numbering Unit
50 Ludgate Hill, London, EC4M 7JJ
Enquiries - Telephone: 0171 634 8758; Fax: 0171 634 8943
Numbering Bulletins are published monthly by the Oftel Numbering Unit. The same information can be found on the following Warwick University pages:
http://www.warwick.ac.uk/WWW/search/oftel_cl.html and http://www.warwick.ac.uk/cgi-bin-Phones/nng
Issued by the Oftel Numbering Unit
50 Ludgate Hill, London, EC4M 7JJ
Enquiries - Telephone: 0171 634 8758; Fax: 0171 634 8943
The consultation on the Numbering Scheme ended on 31 October. By that date 164 responses had been received; copies are available for public inspection in Oftel's library. The comments are now being considered within Oftel and by the Numbering Advisory Group (NAG). The next meeting of NAG is at 2pm on 15 November. Oftel intends to make a Statement on the outcome of the consultation in December.
Update on current position
Number portability is being introduced gradually to different categories of numbers. Some operators are already offering portability of geographic (01) numbers in parts of the UK. Over the coming months this will be offered by more operators and available in additional areas of the country.
Portability is also being extended to other categories of numbers. Work is currently underway to introduce, by next summer, portability of numbers for Specially Tariffed Services (Non Geographic Number Portability - NGNP). Trials between operators are due to begin in the spring of 1997 (see below for details of prefix codes).
Responses to the Consultation on the Numbering Scheme showed strong support for the early introduction of portability of mobile numbers. Technical options for portability of mobile numbers are being evaluated with industry and Oftel will be seeking rapid progress in this area.
Non Geographic Number Portability Prefix Codes
Agreement has been reached on the form and ranges of numbers to be used for NGNP Prefix Codes and the Numbering Unit is now making allocations to operators requiring them.
The form and range of the NGNP Prefix Codes is 504XXX, with normally one (max. two) codes allocated per operator licence (thus for Cable Companies a code per Franchise Area may be allocated). The range 5049XX has been agreed to be used for individual operators' internal network use.
The Numbering Unit is receiving an increasing volume of queries regarding the differing schemes found on dials and keypads in the UK. The current position, expressed in B1.4 of the Numbering Conventions, is that the general use of letters is not encouraged. This position has been endorsed by the European Telecommunications Office in advice to the European Commission (see below).
The general use of letters on dials ended in 1966 with the introduction of All Figure Numbering. However, letters on dials have been used commonly on mobile handsets and are now being reintroduced by some suppliers on new fixed phones. This market move to promote letters on dials of course does not affect the installed base of fixed phones without letters on dials. In addition, mobile phones appear to have at least three differing arrangements (many new mobile phones are now converging towards the ITU's E.161 Option A arrangements).
The proliferation of arrangements (there are no adopted standards in the UK) and the installed base of fixed phones without letters on dials means that certain Alpha-Numeric combinations will not always be reachable when letters are used. The Numbering Unit at Oftel is responsible only for the issuing of blocks of numbering capacity using the decimal character set 0-9. It is for the Operator to decide whether a letter combination is feasible when numbers are issued. In particular, Operators should be aware of difficulties when using the letters O, Q and Z.
The Numbering Conventions list a suggested format which has now been overtaken by an ITU-T recommendation, E.161 Option A. At the end of 1994, when Oftel consulted on the significance of E.161 Option A, the consensus was that it should be adopted for the future. For information, the ITU-T E.161 Option A format is reproduced below:-
Oftel has been advised that the above scheme has been recently adopted by ETSI for GSM and is recommended by the European Telecommunications Office as a future European Standard. It should be noted that this recommendation differs from current practice in the USA, where the letters Q and Z are not present on landline telephones. The same arrangement has been adopted for keypad layouts for text and office systems by the ISO/IEC and is described in BS ISO/IEC 9995-8. There are currently no firm plans to make the introduction of letters on telephones mandatory; indeed the advice of the European Telecommunications Office to the European Commission is that:
At the last Numbering Advisory Group meeting it was agreed that, to preserve numbering migration options, new decades of DE Blocks in Geographic Codes should not be opened if blocks were available for allocation in other DE decades which were already 'open' (ie already have allocations made from them).
Operators and CPE maintainers are advised that the following D digit ranges should be opened up in the following Extended Link Numbering Areas (ELNS) with effect from 01/11/1997:
Area Code(ELNS) Area Range to open
1423 Boroughbridge 2X
1423 Harrogate 6X
1507 Alford (Lincs) 2X
1507 Spilsby 7X
The block 1222 32 allocated in Cardiff to BT in October is an exchange for the block 1222 20 which is now shown as Free.
The Status of a number of codes in the Personal Numbering Range has been changed from Protected to Free. This has been done where the D digit in the corresponding S-Digit 1 code is not used. Protection of codes where the corresponding S-Digit 1 code is used will remain until April 1997.
Changes made to the Specified Numbering Scheme during October and in the period August
to October are summarised below. Annex A gives further detail of the changes made in the
period August to October. In the case of the Area Numbering range, only Allocations and
Reservations are shown. Detail of other changes, e.g. Protected blocks becoming Free are
shown
on the Oftel home pages on Internet.
Oct Aug-Oct
Area Numbering Range Allocations
43
141
Reservations
3
16
Other
Changes 273 3462
Mobiles Numbering Range
Allocations
1
12
Reservations
0
10
Other
Changes 0
1
Personal Numbering Range
Allocations
1
3
Reservations
0
1
Other
Changes 0
11
Special Services Numbering Range
Allocations
4
29
Reservations
0
0
Other
Changes
0
0
Access Codes
Allocations
1
6
Reservations
0
0
Other
Changes
0
12
Total Number of Changes 326 3704