Quote:
Originally Posted by diabloo Example: There is no correlation between Airtel & Vodafone numbers for region. |
Depends on when the series were released. If you see the first set of operators, they followed a sequence for each state. Eg: 9845 was JTM (now Airtel Bangalore) and 9844 was Spice. Similarly in Delhi it was 9810 for AirTel and 9811 for Essar (now Vodafone); for Bombay it was 9820 for for Orange (now Vodafone) and 9821 for BPL (now Vodafone); for Chennai it was 9840 for Skycell (now AirTel) and 9841 for RPG (now AirCel). Calcutta had 9830 and 9831.
Then the 3rd operators came in, BSNL/MTNL came in, the 4th licenses were released and now we have a whole set of numbers. The backdoor entrants Reliance also had to be accomodated so they were given 93. Since Reliance got themselves a Mobile license they had to issue the same to Tata Indicom too, so they became 95.
There is a long history to this. You also need to refer to page 107 of the first document which states:
NUMBERING FOR CELLULAR MOBILE NETWORK
ALLOTMENT OF MOBILE SWITCHING CENTRE (MSC), SIGNALLING POINT (SP) AND MOBILE NETWORK CODES (MNC) FOR CELLULAR OPERATORS
1. The cellular mobile network has been divided into 19 service areas and 4 metropolitan cities for which licenses were issued. Accordingly Numbering Plan was formulated for allotment of MSC code for each operator with spare codes for future allotment.
The format of cellular mobile service Numbering Plan is given below:
ACCESS CODE - MOBILE SWITCHING CENTRE (MSC) CODE - SUBSCRIBER NUMBER
2-digit 3-digit 5-digit
98/94 etc. ABC XXXXX
· Presently level ‘98’/’94’ have been allocated as access code for mobile networks.
· ABC=’000’ to ‘999’. However, ABC=’000’ to ‘099' have not been
allocated and are reserved.
· XXXXX= 00000 to 99999.
Initially in each service area/metro, two operators were given licence to operate. With further opening up of mobile services, two more operators are permitted to operate in each service area/metro areas.
The Signalling Point (SP) codes for mobile operators are given in
9000/10000 series. The MSC codes and SP codes allotted to the cellular mobile operators in different circles/metros are also listed in Table-1.
Quote:
Originally Posted by diabloo For STD:
Bangalore is 2 digits, Mysore is 3 digits & Mandya is 4 digits. |
Lookup the numbering plan document. There are codes allotted for Long Distance Charging Areas (LDCAs) and Short Distance Charging Areas (SDCAs) which are different classifications for areas. The total length of the number should not exceed 10 digits and therefore they reduce or increase the length of the Trunk Code according to the capacity of the exchange. Obviously Mandya does not have the same number of telephones as Bangalore has - so how do you keep the total dialling string to 10? INCREASE the SDA code.
To Quote from Page 16:
LINKED NUMBERING SCHEME FOR PSTN
1.1 INTRODUCTION
1.1.1 Indian Telecom Network is divided into number of LDCAs. Each LDCA
consists of one or more SDCAs, which are also known as local areas.
Each SDCA has one or more number of exchanges.
1.1.2 Each LDCA has a Long Distance Charging Centre (LDCC), which is a
Trunk Automatic Exchange (TAX).
1.1.3 Each SDCA has a Short Distance Charging Centre (SDCC). Normally each SDCC is an integrated local-cum-tandem or a transit switch. In certain cases SDCC itself may also be LDCC.
1.1.4 Each SDCA normally covers one or more taluka or other administrative areas. The size of SDCA generally varies between 800 sq. kms to 2000 sq. kms.
1.1.5 As per the National Fundamental Plan 1993, the N(S)N is of 9 digits
including 2 to 4-digit National Destination Code (SDCA Code) and 7 to
5-digit subscriber number. This excludes the access code ‘0’.
1.1.6 Most of the SDCA’s have 4-digit trunk code, leaving 5 digits for subscriber number. With 5-digit length, only about 50,000 subscriber numbers per SDCA can be provided. If the subscriber base increases beyond 50,000 in an SDCA, either the number length will have to be increased or another trunk code will have to be allotted. Further, there are more than 700 SDCAs (with 4-digit code), which have more than 10,000 subscribers and are expected to grow more than 50,000 in next 30 years. These would need 6 digits local numbers. This would increase the total number length to 10 digits or else SDCA code will be required to be reduced to 3 to keep N (S)N of 9 digits. Since only about 150 spare 3-digit codes are available, only alternative is to increase the number length. The scheme envisages the use of SDCA based linked numbering with 10-digit N(S)N.
1.1.7 With the migration to uniform 10 digits SDCA linked numbering scheme, N (S)N would have following variants:
SDCA code - Subscriber Number
2-digit - 8-digit
3-digit - 7-digit
4-digit - 6-digit
Quote:
Originally Posted by diabloo Thanks for the links. They prove my point. |
You do not have a point, therefore dont bother trying to prove something.
It is very easy to pass judgement on such matters based on superficial perception. It takes a lot more to understand the effort that has gone into such plans.
I would recommend that you first read the documents and then present your arguments in a logical manner based on what you have read. The national numbering plan is not without its weaknesses, primarily because it is outdated but that does not mean that the numbering plan is random or unplanned or based on whims and fancies.