Re: [tlug] Best communications-enabled, efficient visit

[Benjamin Kowarsch <trijezdci@example.com>]

On 16 June 2016 at 23:16, Kalin KOZHUHAROV wrote:

AFAIK, multiple SIMs use the same baseband radio, think of it more
like network card with multiple IP addresses.

A mobile phone RAN is not designed like an Ethernet LAN.

The design is based on the assumption that each mobile station (the phone) has a single IMEI (International Mobile Equipment Identifier, somewhat similar to an Ethernet MAC address) and a single IMSI (International Mobile Subscriber Identity). I doubt you could share a conventional transceiver unit between two separate IMSIs and networks simultaneously.

You could do it if you had an SDR (software defined radio) based handset. However, at this time SDR is largely confined to base station technology and even when it will arrive one day on handsets, regulators will almost certainly require handset manufacturers to lock down the radio so it cannot be repurposed for anything other than it has received approval for.

With current handset technology, a dual-SIM that permits you to simultaneously sign on with both SIMs is almost certainly going to have a dual-transceiver. The transceivers will likely share the antenna but otherwise they will be like two separate radios in a single device.

 

I've read about some quad-SIM phones often used in Asia.

Hmm, Wikipedia kind of disagrees with me. Well, I tried:
https://en.wikipedia.org/wiki/Dual_SIM

:-)
 

Somewhat recent phone that I was looking at:
http://www.androidcentral.com/dual-sim-unlocked-phones-do-you-need-one

Quite interesting, but it says that the second SIM can only do 2G.

But thanks for the link for that Zenfone.