Data rate

Scott · Posted: Sun May 09, 2004 10:30 am Post subject: Data rate

Does anybody have an idea as to TMC bandwidth requirements?

My existing mobile tariff includes 500kB of GPRS data a month. I'm hoping this will be enough to make reasonable use of the TT3 traffic feature (when it becomes available). Am I being overly optimistic?

DavidW · Posted: Sun May 09, 2004 2:05 pm Post subject:

I think you're mixing up TMC (which is carried on RDS via FM radio) with TomTom Traffic.

When TomTom Traffic becomes available, I should be able to give people some idea of the usage. I don't much mind if I use two or three MBytes per month; I'm paying GBP2.35 per MByte (including VAT) for GPRS Internet on my Vodafone contract. Obviously it depends exactly how much you use it, but I can't think it's going to transfer that much data over GPRS.

Are you sure that your included 500KBytes is GPRS Internet? That sounds more like the sort of allowance you'd get for GPRS WAP - particularly with O2 online.

GPRS WAP is almost certainly useless for TomTom Traffic. The chances are that you'll need full GPRS Internet access. If you can open web pages in Pocket Internet Explorer over GPRS you should be all set.

David

Scott · Posted: Sun May 09, 2004 5:48 pm Post subject:

DavidW · Posted: Sun May 09, 2004 7:02 pm Post subject:

There is a distinction - you can only access whatever APNs you're permitted by the network to access. A WAP APN will only give you access to a WAP gateway, which you can't use for general Internet traffic.

There are such things as closed APNs for access to private networks and/or to allow VPN usage where it's generally not allowed to all subscribers (unless it's changed, ordinary Orange users can't use VPN via orangeinternet though I believe some Orange business customers do have VPN facilities).

David

Scott · Posted: Sun May 09, 2004 9:15 pm Post subject:

I see. Thanks.

I've since checked my phone and there are two different GPRS accounts. One for WAP and one for general internet access (to which the 500kB allowance applies). The WAP one appears to be used for picture messaging.

DavidW · Posted: Mon May 10, 2004 9:26 am Post subject:

vicky · Posted: Wed May 12, 2004 7:45 am Post subject:

Hi, the codes used in TomTom3 Traffic are TMC not the Trafficmaster variety, hence the differences between Taffic-I and TomTom Traffic Reporting (Taffic-I uses Trafficmaster Data), TotTom3 Uses TMC, as is shown by the TMC Data and display paths in the software,

As for Saying TMC is a radio only format, this is incorrect, the quote below is from the TMC Website, (Link below for more detailed fully descriptive article)

DavidW · Posted: Wed May 12, 2004 7:33 pm Post subject:

Indeed - my apologies for not helpfully distinguishing carrier issues (that is RDS-TMC as opposed to traffic data, which can be TMC, over GPRS) versus TMC as a technology.

I had originally read the question as about the architecture of RDS-TMC - then scrubbed my response when I realised it was TomTom Traffic being talked about.

I guess such mistakes on my part come from trying to answer a lot of posts fairly quickly. You're quite right, Vicky - TMC is not just an RDS technology.

David
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