Option XYFI 3g speeds

[dabean]

I bought an Option XYFI to use in my car, but the speeds aren't what I hoped for.

Here are some tests I did this morning:
[table="width: 500, align: center"]
[tr]
[td]Cell C (XYFI as hotspot)

[/td]
[td]Cell C (XYFI as USB modem)

[/td]
[/tr]
[tr]
[td]Vodacom (XYFI as hotspot)

[/td]
[td]Vodacom (XYFI as USB modem)

[/td]
[/tr]
[/table]

I ran each test at least 5 times and the results were similar every time. I then put the Cell C sim in my laptop (using the built-in 3G modem) and this:

All of the above tests were done on my desk this morning (had to work in between so the times may vary a bit).

In the car I generally get 0.2Mbps down and 1.2Mbps up (Cell C). The Vodacom sim is my work number and the Cell C is a contract that I never use the data of. I'd like to use it to stream internet radio, but it buffers every few seconds so I use my phone's 3g instead.

Do you think the problem is at Cell C, the XYFI, or both?

 

[sajunky]

There are two different modems giving similiar results with Cell C. It indicate that modem is not faulty. Higher uploads speed suggests that there are strong interference in your office affecting receivers. You can't compare directly Vodacom and Cell C, as they use different frequencies. More testing should be done with Vodacom SIM, as XYFI as USB modem tests are positive. It could be position/orientation of the modem which matters, by example. What is the signal strenght?

 

[dabean]

Thanks for the reply

This is the only place I've found where you can see signal strength:


The slow-download/fast-upload thing is the same everywhere. Well everywhere I've been in the past two days. My office -> wife's office -> home and in-between. Probably around 30 square km. I've made a point of running the speedtest app when I stop somewhere to see if it's just one tower.

I first used the 12V socket in the cubby-hole but have tried the one next to the ashtray (vertical vs horizontal orientation), no difference.

Getting another Vodacom SIM kind of defeats the purpose, I only bought the XYFI to use up the Cell C data that's been going to waste.

 

[sajunky]

Stick it in the midle of the windscreen, back cover facing outside (the place antenna is most likely). Any better? Inside the car reception in not good.

 

[WireFree]

Here are some results from a deskbound XYFI (v3.0.0 firmware). I tested with the different Speedtest.net servers by selecting them manually.
Laptop with WiFi to XYFI
MWeb: http://www.speedtest.net/result/2638439898.png
MTN Business: http://www.speedtest.net/result/2638459494.png
Cell C: http://www.speedtest.net/result/2638463578.png
Neotel: http://www.speedtest.net/result/2638465505.png
Vodacom: http://www.speedtest.net/result/2638472014.png

Laptop with XYFI in the USB port
Cell C: http://www.speedtest.net/result/2638490813.png
MWeb: http://www.speedtest.net/result/2638493606.png
MTN Business: http://www.speedtest.net/result/2638495314.png

Laptop with Cell C ZTE E1820 USB Modem
Cell C: http://www.speedtest.net/result/2638503370.png

A did get the occasional test where the upload was faster than the download. A repeat test a few minutes later has the download faster than the upload again.
Likewise radio network conditions, network capacity to the Internet, intercepting caching proxy servers and load to the Speedtest.net servers may also affect the results.
The MTN Business server's results for the WiFi tests are not consistent with the other Speedtest.net servers. However, a while later when the XYFI is in the USB port the MTN Business server's results are consistent with the other servers and it is much faster than the earlier test via WiFi.

Also note that while you are driving there is also likely to be handovers between base stations, which may result in dropped IP packets. Depending on the application you are using and the lower level protocols it uses, performance may be affected during packet loss. The standard TCP protocol will throttle back on the transfer rate when a packet is dropped, as standard TCP from a wired network interprets packet loss to imply network congestion. (There are TCP implementations for wireless networks that do not throttle back as aggressively.)

 

[dabean]

Thanks, at least I know now that the unit isn't faulty.

I did some more tests today and saw that my hotspot results from yesterday weren't accurate. The XYFI was running in USB + Hotspot mode for that test which adds extra load on the XYFI. Unistalling the driver on the desktop gave speeds in line with your results.

Hopefully the Cell C speeds in my area improve someday.