REVIEW - MIO A701 - First PDAPhone with SiRFIII and AGPS


The Mio A701 is a smart looking and compact PDAPhone

1. Very fast Time to First Fix (TTFF) with SIF AGPS : I did some side by side Time to First Fix testing (TTFF - further explained here) with other SiRFstarIII receivers, the Eten G500 and the Globalsat BT-338. Thanks to SiRFinstantFix (SIF), AGPS over the internet (see this preview), the Mio A701 clearly stands out : impressive cold start of 12 seconds (technically called "warm start") after being turned off for 4 hours, behind a non coated windshield in an urban environment without tall buildings, compared to the 45/60 seconds for the BT-338 and Eten G500. Warm start (hot fix) as when you leave a tunnel are identical at about 2 seconds. Without SIF, the A701 will behave like the Eten G500 or the BT-338.
   
   So SIF does clearly offer a significant benefit, provided you use it properly, i.e. connect to the virtual COM4 port and not to the physical COM2 port. SIF can then play its part by feeding ephemeris data downloaded over the internet to the GPS chipset when it normally has to download it directly from the satellites at least every 4 hours, a process that takes 30 seconds in good environments and much longer in degraded environments (high-rise buildings, trees, coated windshield) and can be impossible if the signal level is too low (<28 dB-Hz). While it doesn't have a lot of practical use I did some indoor TTFF testing and the A710 managed to get a "warm fix" in 20 seconds in my kitchen when it took the BT-338 and G500 7 minutes. More practical to get off to a good start in the morning, in my garage where the signal level was about 24dB-Hz, it fixed in 60 seconds and as expected the 338 and G500 couldn't.
   
   I'm preparing a full article about AGPS over the internet, but some quick comparisons with Globallocate's LTO solution used on the HP hw6515 shows that it is a bit slower in good conditions, with 12 seconds on average versus 5 for the 6515 but it is more consistent and works in more environments thanks to the higher sensitivity of the SiRFstarIII chipset and possibly larger antenna. The downloaded data weighs about 50Kb and remains valid for 3 days on the Mio, versus 2 and 40Kb on the 6515 but it can be extended to 10 on the latter (80Kb).



TTFF testing, best case scenario with a re-radiating antenna, then it gets worse in the kitchen and the garage!


2. GPS Navigation Performance : While AGPS makes a significant difference for TTFF, it normally has little impact on navigation performance as the ephemeris will have been downloaded the normal way by that time...provided the signal level is good enough and we'll see that the A701 still keeps some edge in test #2.
   
   TEST #1 - COATED WINDSHIELD
   As I'm currently working on an article on the negative impact of coated windshields on GPS performance, I did some A710/G500 comparisons in this hostile environment, so the tracking errors areNORMAL and are not present in Test #2 below or in the track of the GNS5843 placed under the rear window. This test run was done in the small streets of Nogent sur Marne outside Paris and SIF was not activated on the A701.
   
   
   The impact of the Citroen C5's coated windshield can clearly be seen, with small errors in open areas and significant problems in dense areas. The A701 and G500 really struggle to keep track and the resulting guidance with road navigation software would be confusing. The GNS5843 placed in the rear doesn't show any such problem of course.
   
   
   The Mio A701 and the G500 perform similarly with no lost fix, which would indicate good tracking with the previous SiRFstarII generation, not so with SiRFstarIII something quite confusing to inexperienced users who equate satellites in the fix with good accuracy.
   
   TEST #2 - NORMAL WINDSHIELD
   This test run was also done in the small streets of Nogent sur Marne this time with a Mio A701, Eten G500 and HP hw6515 lineup, side by side behind the non-coated windshield of a Citroen Xantia.
   
   
   Good tracking performance overall, with the A701 coming out on top for accuracy, followed closely by the G500. The 6515 is still behind in spite of the latest v2.03 GPS drivers, but the resulting guidance would remain usable with road software.
   
   
   This signal analysis is interesting in that it shows that with a slightly less sensitive antenna, the A701 can still get a better fix on average than the G500, likely because it tracked a satellite (SiRFIII can track down to 15dB-Hz) for which the G500 could not download the ephemeris due to its low signal (>28dB-Hz required).
   
   
3. GPS Firmware : version 3.3.0, when up to now SiRFstarIII receivers had been programmed with 3.1.1, likely related to the implementation of SIF


4. External antenna connector : uses the standard MMCX type and will be useful for driving in dense urban areas with a car equipped with a coated windshield to maintain a good level of accuracy


5. Battery Life in GPS use : In my usual testing conditions, full backlight and continuous GPS use, the Mio A701 offers an excellent battery life of 300+ minutes compared to 270 for the G500 and 293 for the Asus A636
   
   A slight "bend" around 40%, with possibly some power saving mode kicking in automatically


6. GPS Software Compatibility (connexion tips) and TomTom 5 trip timings : my test model came with MioMap v2, an adaptation of Navigon 5 and I got it to run Route66 and TomTom v5 successfully. However to keep the full benefit of SIF you must use the virtual COM4 port at 4800bps and not the physical COM2 GPS port at 57600bps (Mio should probably have hard-coded this to avoid user error). With TomTom 5 and Route 66 you need to "wake up" the GPS first with a utility like VisualGPSCE a forum favourite. Works well in both portrait and landscape modes, with the usual slowdown in the latter case, courtesy of the Windows Mobile software rotation. Trip calculation time is about 20% longer than on the Eten G500 with a 900km Paris-Menton requiring 23 seconds versus 18 (same miniSD card).
   
   You must "wake-up" the GPS with VisualCE to use the COM4 port and benefit from SIF



7. Car Holder : Like the G500 and unlike the 6515, the A701 comes with a custom car holder that can rotate



Portrait mode, rotating cap, landscape mode


8. Data Connexion Speed
: The Mio A701 is limited to GPRS, but the speeds are quite good with 55kbps on average, a record compared to the standard 30kbps I'd experienced so far on various phones and on the Eten G500. Still a far cry from the 130kbps offered by Edge connectivity on the HP hw6515. For standalone use it is quite usable, but using it as a modem with a laptop is going to be problematic, something the 6515 can handle pretty well.


9. Bluetooth : it uses the Microsoft "stack" versus a custom stack on the G500, so no A2DP stereo profile and no AKU2 upgrade planned at this point



10. Overall Thoughts and Conclusion : Unlike the Eten G500 that feels a bit like a "brick", the A701 is a pleasure to carry around and look at, slightly reminiscent of the sleek Qtek S100 and it also comes with a convenient horizontal belt case. While it doesn't feel as slow as a WM5.0 upgraded Axim x50v it certainly isn't as "snappy" as the G500 or as the WM2003SE HP hw6515 and can have its slow moments, but remains pleasant overall. GPS fans will be excited by the first and successful implementation of SiRFInstantFix and all will enjoy the added level of comfort it brings. The lack of Edge connectivity and of a physical keyboard will prevent it from replacing my trusty HP hw6515 though.

Compared to the HP hw6515 and Eten G500

quote:

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Originally posted by gpspassion

Yes I was happy to figure out the COM2/COM4 part, took me nearly a week ! Honestly I'm not too bothered by having to launch VisualGPS, then TomTom and then stopping VisualGPS if I don't need to log data. MioMapv2 works fine with COM4 so I don't think there is a huge incentive for Mio to make the 701 compatible with other software. TomTom could of course, but it works on COM2/56700 so it depends on how much time they can spend on this. Tough call.

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