This is the problem. His phone frequently stops receiving phone calls and messages even when his phone shows a maximum signal in respect with the tower. If he tries to call someone, it will call. If someone tries to call him, the call goes to the voice mail.
This is not a problem of the device he is using: he has tried to use an iPhone, an android phone and even a crappy old mobile phone. All present the same problem.
I suspect this is a crappy cell phone network but he has switched networks recently and the problem persists.
I have tried to call him from my landline phone in Europe and from SIP services like Browsercalls, that use centrals in China and Luxembourg.
He wants some solid evidence to complain and even sue the company that charges him a pile of money every month for this crappy service.
How can we gather evidence about this problem?
Is there a way to test his network from the web or locally?
Spectrum is a limited resource. Therefore, mobile carriers need to reuse their frequency bands without causing interference. This problem (Frequency Assignment Problem) can be modeled as a graph coloring one. Mobile networks operators nowadays use frequency division or Code division to let multiple users to connect to the network.
In GSM networks, frequencies are assigned to base stations and are used to link between cell phones and the nearest base station. Base stations are assigned more frequencies in the cells (geographic regions) having high demand
3G networks use frequency division, other networks use code division (CDMA), and LTE (4G) networks use Orthogonal Frequency division (OFMDA).
Questions
A) Are these little frequency bands:
- assigned by user (mobile phone): A base station communicating with N phones needs N bands.
- Or are they shared between phones using an access control protocol (like CSMA/CA for example): A base station communicating with N phones needs M bands. with M <= N.
B) What is the difference between old school frequency division and OFDMA?
C) Can all of these methods (Frequency division, OFDMA and CDMA) be modeled as a graph coloring problem?
Links to good reading (or video) materials will be appreciated.
Hiya,
If there's a more cell/mobile phone oriented sub that I haven't found that folk think this would be appropriate in, feel free to point me that way. In the meantime, here's the issue that I'm looking to solve :
My dad emigrated to Australia (Melbourne) from the UK a few years ago. He runs his own UK business and continues to do so via the magic of Skype and whatnot. It's a small business, and very much built on 20+ years of personal contacts within his particular industry.
For that reason, he has had the same UK Vodafone telephone number for...well...ever. The only time it ever changed was when the UK mobile number prefixes changed - he has genuinely had this account since at least 1991 when he had one of those actual car phones built into his Volvo.
Here's the thing. He still has it. And still uses it. In Australia. So yes, his mobile bills are immense. To be fair, he does use Skype for outgoing stuff, but, of course, he pays for the international portion of incoming calls as well, as it's a UK number.
So my question is - how best to deal with this? A fallback option is to leave his mobile in the UK with his secretary and have her answer that, and get himself a local Oz phone, but it's not perfect. Is there any cost effective way to keep the UK number but divert it to an Australian one, or even to a SkypeIn number?
Failing that, with the fallback option, can any Aussies recommend a provider, or have Telstra got it all sewn up?
Thanks for any advice in advance :)
Spectrum is a limited resource. Therefore, mobile carriers need to reuse their frequency bands without causing interference. This problem (Frequency Assignment Problem) can be modeled as a graph coloring one. Mobile networks operators nowadays use frequency division or Code division to let multiple users to connect to the network.
In GSM networks, frequencies are assigned to base stations and are used to link between cell phones and the nearest base station. Base stations are assigned more frequencies in the cells (geographic regions) having high demand
3G networks use frequency division, other networks use code division (CDMA), and LTE (4G) networks use Orthogonal Frequency division (OFMDA).
Questions
A) Are these little frequency bands:
- assigned by user (mobile phone): A base station communicating with N phones needs N bands.
- Or are they shared between phones using an access control protocol (like CSMA/CA for example): A base station communicating with N phones needs M bands. with M <= N.
B) What is the difference between old school frequency division and OFDMA?
C) Can all of these methods (Frequency division, OFDMA and CDMA) be modeled as a graph coloring problem?
Links to good reading (or video) materials will be appreciated.
