[Eurfyl]

I am struggling in finding information on the maximum number of users that can be connected on to 3G/UMTS in one cell. Is there a maximum and then number of users beyhond that maximum will not get a connection or does the quality of service just keeps degrading with increasing number of users. What about GPRS? Is it the same? And gsm voice call?

Any clues would be much appreciated....

[3g-g]

For 3G it depends on the capacity of the link to the WBTS and what the users are doing and how near/far they are away from the site itself, it also depends on what they're doing, you can have more users if they're all just doing voice, but if you start using higher bandwidth applications such as data or video calling then the number of users able to use the resource of the site will drop. The bigger the pipe in the more it can do. Once the node is at capacity and doesn't have the resource to assign to new users you'll usually get a network busy notice.

For 2G GPRS is depends on how many transmitters are in the site in question, how much voice traffic is on it to allow the timeslots to be used for GPRS or whether the operator has allocated specific transmitters to deal with GPRS only. Again, it's all dependent on how the operator has set it up. Bigger city centre sites will be able to take a fair chunk of GPRS traffic, rural low capacity sites will be limited.

GSM voice calls work in the same way as GSM GPRS, more transmitters the more traffic it can take, it all depends again on how many transmitters are in a sector. Busier areas get more transmitters, there's no rule as to how much traffic a specific site will take, it'll differ throughout the country.

I know that's not specific to the questions you've asked, but there isn't really a specific answer to give I'm afraid!

If there's anything else just fire it up.

[Eurfyl]

Thanks for the responce.

So is there no time slots involved with 3G as is the case with GPRS?
How many time slots are there with GPRS; and if you are the only user in a cell then do you get all the available timeslots?

Thanks again

[bsrjl1]

Thanks for the responce.

So is there no time slots involved with 3G as is the case with GPRS?
How many time slots are there with GPRS; and if you are the only user in a cell then do you get all the available timeslots?

Thanks again

The are sort-of timeslots in 3G, but they're not as strictly defined as in GSM. Basically there is a frame structure to most of the physical channels & some of them only occur at different times - this is all detailed in the SIBs that are broadcast as part of the cell. You can tweak these to increase cell range, call capacity or power. As 3g-g says above, transmission is a limiting factor for a 3G cell, although scrambling code use is also important.

As far as GPRS goes, it's upto the operator to define the min & max number of TSLs available. They usually dedicate one to broadcast the PBCCH (although this can be incorporated in the BCCH for rural sites), and let GPRS fill up the remainder.

Depending on the GPRS class of your handset, you can use a maximum of 5 out of 4 UL & 4 DL TSLs. So in answer to your question, no - at most one user will only use 4 out of the available DL TSLs.