One SIM, 2 SPs

[DaveO]

I have asked this in the Vodacom forum, but never found the solution that I want ( Solutions / Options - Yes, the one I want - No ).

Prehaps someone in the MTN forum might have some ideas.

I have 2 SIM cards, 1 Vodacom and 1 MTN. Each with its own number ( 082... & 083... ).

At present, I have to swap cards in my phone ( Nokia 6820 ) to get the best signal / gprs / edge coverage, depending on where I am in the country.

The phone does have an option to select the operator manually ( it lists Voda, CellC and MTN ).

Can I use the same SIM card for both MTN and Vodacom connections ?

If so, how can I get it set so that it has the correct cell number when I select and set the operator manually ( ie. the 082 number when Vodacom is selected as the opetaor, & the 083 number when MTN is selected ) ?

Regards
Dave

 

[Insider]

One SIM is linked to to only one operator. You may have more than one number linked to a SIM (e.g. separate numbers for data and fax) but they all sit together on a single user profile within the network architecture.

So - no sharing of numbers across different operators.

 

[DaveO]

OK, so if the 'link' is on the SPs system, why can't a different SP link that same SIM ID to another number on the different SPs network?

I could then change my operator from MTN to Vodacom and the Vodacom system should detect my SIM ID and link it to my Vodacom Cell Number ( as if I had just switched on my phone ), whilst the MTN network would just think that I have disconnected from them ( as if I have switched the phone off ).

Sounds pretty simple to me, just can't understand why it can't be done. Are the SIM IDs manufactured in specific ID ranges for specific SPs ?

 

[Dolby]

Yea ... does sound right actually.

Done some phones have a Line 1 and a Line 2, like the old Siemens SL45i? I think one the old Samsungs had place for 2x SIMS in the phone

 

[MTNBroadband]

The Line 1 and Line 2 on some handsets usually relates to a separate type of service (two lines with the same operator) which is also not available.

To use two operators you have to have two physical SIM card readers connected to one device to achieve what you want to achieve.

(An expensive alternative is to purchase a SIM from T-Mobile UK and then manually select your roaming operator )

 

[bosun]

OK, so if the 'link' is on the SPs system, why can't a different SP link that same SIM ID to another number on the different SPs network?

I could then change my operator from MTN to Vodacom and the Vodacom system should detect my SIM ID and link it to my Vodacom Cell Number ( as if I had just switched on my phone ), whilst the MTN network would just think that I have disconnected from them ( as if I have switched the phone off ).

Sounds pretty simple to me, just can't understand why it can't be done. Are the SIM IDs manufactured in specific ID ranges for specific SPs ?

There are a couple of points to raise here

Don't confuse the SP and the Network Operator (NO)

Your SIM is configured to work on a given network where you are registered on the HLR (Home Location Register). When you go roaming you register on the VLR (Visitor Location Register). By default your SIM will choose the HLR when it can.

It is theoretically possible (although these days unlikely to happen) that an MTN subscriber may find themselves in an area where MTN offers no coverage but Vodacom does. You could then roam on the Vodacom Network. Your calls would be carried on the Vodacom network, and they would then on bill MTN for your usage, who would in turn bill you. You would still, however be regarded as an MTN customer using the Vodacom infrastructure. BTW this is exactly what happens to CellC customers.

Which network you "belong" to has nothing to do with number portability (which I saw you raised on the Vodacom forum as being a reason to be able to choose networks). When you port your number from one network to another, you will be issued a new SIM. It is via the SIM that the NO knows who you belong to, and hence where to route the call billing data to.

So, the short answer to your question, and I'm sure you are sick of hearing it, is "It can't be done"

What may be possible in the not too distant future is sophisticated handsets that can perform a sort of LCR function, and choose which bearer to use, e.g. GSM, VoIP, Wimax, Bluetooth etc. However this will require "advice of charge" info to be available up front and will doubtless be quite complex. It will also mean, of course, that you will most likely be billed by multiple entities for effectively the same services and you might not know in advance which service you are going to use. At the end of the day, for post paid customers at least, you will need a contract with each of the providers for this to be possible.

 

[MTNHandsets]

Yea ... does sound right actually.

Done some phones have a Line 1 and a Line 2, like the old Siemens SL45i? I think one the old Samsungs had place for 2x SIMS in the phone

There were some old phones out that did this, for example the Benefon Twin - (I think this product may still be available from Benefon). It seems to have been an extremely niche market though, so they never really took off. We also saw cover accessories for some products that did this, but of course this required firmware upgrades for products that were not always endorsed by the Manufacturer. This of course compromised warranty.

These solutions were not very elegant either though, switching SIM's always required a power cycle of the phone.

Unfortunately this is the only way I know of that this could be done currently.