Blackberry 8707 - IP Modem

Thursday 24th August, 2006
I'm writing this entry over 3G wireless connecting to the remote client over Microsoft remote desktop (RDP). It's not the fastest link in the world, but far from slow too, it's pretty much keeping up with my typing so I'd approximate 200Kb speed as I'm using RDP in true colour. In fact, a trip to the speed test should help me out no end in giving a true estimate of available bandwidth.

First I need to download the Sun JRE, to enable the speed test java applet to work. I've switched back to my wired machine to continue writing the article and I'm noticing that the RDP speed is no slower on the wired 8Mb connection...the bottleneck is clearly the remote end and not the 3G connection.

Downloading the JRE (7MB) took longer than originally planned. During the file cabinet download process, I intentionally made a phone call from the Blackberry. Being 3G, and not GPRS, the data connection is suppose to stay up. All appeared good and then I ended the call...the download stopped. The scientist in me made me repeat the test and 2nd time through the phone call had no effect so I can only conclude that concurrent voice and data works just perfectly...the download bytes just clocking up in the WinXP dial-up connection monitor at around 45KB/s...glad it's not my bill!

I've just got another cabinet failure during the download, although it seems happy with the retry, and I'm wondering if this link can be a little bit latent at times. I notice when browsing the web that there is a big pause when clicking on a URL or 2-3secs and then the page appears almost instantly after all the latent connections have been established.

As I wait for the install to finish, I notice how much the battery on my Thinkpad T42 is being hammered. A full battery at the start of testing, I can see the % figure just clicking down. Clearly the 8707v is consuming a lot of juice and drawing current over the USB connection to replace it. I wouldn't expect more than around 90mins of battery life in this setup, but I am using full bandwidth.

JRE download completed successfully, I've returned to the speed test to run the full diagnostic with detailed output. It's been a while since I've seen the test take this long, but with 8Mb at work and 10Mb at home..I'm not surprised.

The results are in...Downstream 320.9 KBps (= 0.3Mbs) Upstream 58.6Kbps (= 0.1Mbps). So, reasonably quick and some of the latency is explained by the slow upstream link.

UPDATE: For reference, I've just forced the 8707v into 2g (GPRS) mode and repeated the test. In theory, the data throughput should be much slower; but is this true in reality. The answer is "yes"...Downstream 41.5Kbps Upstream 21.6Kbps. 3g wins...flawless victory.

I'm more than happy with this. As an on-call device the bandwidth is just fine for RDP and remote Domino consoles and on the same phone bill at the same time I can make voice calls. My team are going to be happy with their new toys I think, now where's that purchase order form?

My New Arrival
Blackberry 8707v - The Story So Far
Blackberry 8707v - The First Week

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