While inside the conference you have to pay for WiFi, you could surf for free thanks to the Whisher ‘Red Bird’, which carried a mobile hotspot with a 3.8Mbps 3G connection. The signal was encrypted, and we provided the password on flyers handed out by the bird. After three days, we had a total of 87 people connected through this hotspot, which we think is a pretty good number! There was certainly always people waiting around outside, without much else to do than check email or surf the web for a while.
It actually indicates GPRS attachment status, the capability (or lack thereof) of sending and receiving data, be it over plain old GPRS, or the faster EDGE. I was going to comment on the original Engadget blog post, but after seeing a few pages of comments already, I doubt they would have noticed it. This is where they get it wrong:
You’ll notice the iTunes WiFi Store icon, and an O2-UK network symbol up top. If you look carefully, you’ll see that the E logo for EDGE is missing: we guess that 30% network coverage on O2 don’t quite stretch inside the Apple Store.
A bit further down, they mention this again:
O2 iPhone on the left, unlocked US iPhone on the right (running on T-Mobile’s UK network). Note that the O2 iPhone doesn’t show the EDGE logo, but the unlocked phone on T-Mobile does. You can probably guess at what we’re getting at here: O2’s EDGE coverage sucks.
In this particular side-by-side photo, T-Mobile’s coverage is marginally lower than O2’s, but they should both be capable of sending GPRS traffic. Another reason they get this wrong is that the waves icon ‘overwrites’ the E symbol while the iPhone is connected to a WiFi network, so you could still have GPRS/EDGE attachment in the background, so-to-speak. In my particular case, the iPhone is happily registered on Vodafone Spain, and is attached to GPRS (no EDGE here at all), showing the E while I’m not in range of WiFi.
The iPhone also does something very clever – when you open an application that requires a data connection, it will start a GPRS attach and session, while it asks you if you want to join any of the nearby WiFi networks (if any). In case you say no, the alternative data connection is already established, cutting down on extra waiting time before you start seeing content on your screen. This may seem stupid to Europeans, by default stuck with hugely expensive pay-as-you-go data (50 Euro cents per 250kB!!), but with the original AT&T voice + data plan, it does not really matter.
Shame they’re a bunch of morons – they told me taking pictures of their restaurant from the street was illegal (!?). If someone came and took a picture of an ad I plastered on my wall…I’d be more happy than anything, it would mean people notice it (even if it was a competitor). Anyway, if you come to Barcelona, check out Fresh&Ready, not for the food, but for the free WiFi.
I’m pretty amazed at the latest gadgets coming out from the R&D departments of consumer electronics companies, such as Nokia and Apple – the N95 is a super-duper, do-it-all, cellphone (sorry, Nokia wants us to call it a ‘multimedia computer’), featuring multiple bands, HSDPA 3G (Europe only), WiFi, GPS, and a 5Mpixel camera, apart from a wide array of software tools for blogging, posting pictures online, navigation and more. What price does this device pay? A meager 950mAh battery, which lasts less than a day under normal use, considering ‘normal’ as actually using the functionality it offers. I guess you can get more if you turn off the GPS, WiFi, don’t use the camera, and make almost no calls…but then what good are all the bells & whistles for?
The iPhone case is even more interesting, as the device has not been released yet, but Apple has already reported an increase in battery life with respect to the initial quoted value. The iPhone will have 8 hours of talk time, and some 250 hours of standby time, with 5 hours of video and 24 hours of audio playback. Apple’s stock has jumped $3 since the announcement, something that will make losers in the fake email crash happy.
Let’s try to make a simple breakdown of power consumptions, and see if manufacturers are being overly optimistic.
One of the biggest power drains, as there is no built-in power management into the WiFi protocol, contrary to GSM and 3G. When transmitting over GSM, a phone makes calculations from data received from the network and its own measurements in order to adjust RF power to the minimum required to reach the cell’s base station. Thus, in areas of good coverage, a phone can be consuming far less power than in rural areas with more spotty coverage. While on a 3G network, the rate of adjustment is even higher. WiFi chipsets in mobile phones have basically two settings, “high” and “low”. Most times, unless you are sitting right next to the access point, and without any major interference, the setting the phone will use is “high”.
Assuming that the WiFi chipset used by the Nokia N95 and the iPhone use little power, for example, by fitting the Nanoradio solution, the power consumption would stand at 130mA in transmit mode, 53mA in receive mode, and 50uA in standby mode. Assuming we are receiving 80% of the time, for example, by browsing the web, the average consumption would stand at around 68mAh. The N95’s battery would last 13 hours, if it had to power the WiFi chipset alone.
Even though GPS technology has advanced a lot since the early days, GPS chipsets can draw upwards of 80mA. Special trickle-power configurations (which also impact performance) can reduce this to 50mA or so. Thus, the N95’s battery could power the GPS for around 19 hours.
The Nokia N95 features an ARM11-based Texas Instruments OMAP2420 running at 330MHz, featuring 2D/3D video acceleration on top of whopping performance. What does this mean in electrical power terms? Even though this processor features SmartReflex technology, which reduces static leak currents (a good technical overview is available here [pdf]), the net current drawn is around 30mA. The N95 battery could power the main processor for around 32 hours.
The display on the N95 is very good, beautiful, 16M colors, 240×320 pixel resolution. It is also power hungry, taking around 30mA, thus, the battery could also power the display for around 32 hours.
Assuming that you talk 5% of the time on the phone, the average power consumption by the phone subsytem alone would stand around 20mA, resulting in a battery life of 47 hours.
Adding things up
So far, we have seen how much the battery could keep running each individual system on the phone, but adding things up, we have a power consumption of about 100mA (taking into account that we are not using everything at once, I halved the figures). This results in around 9.5 hours of operation, more or less an average day. This ties in with most users’ experiences, as shown in many reviews done so far on the N95.
The iPhone, being much thinner, wider and taller than the N95, probably won’t have that much larger battery capacity – why does Apple give the figures they do, I can only blame on the marketing department. This is not as uncommon as it seems, R&D provides a set of carefully calculated and actually measured results, then the marketing guys take them and multiply them by two. Anyone who has used a modern, high-end phone or PDA, will attest to the fact that quoted battery life figures differ from reality by far. I don’t know of many companies that can raise their stock $3 by simply increasing the value of the battery life in one of their products – this shows how much hype there is around the iPhone (of which I’ll most definitely get one…they are soooo sexy!).
No pun intended, honestly, but Tony Smith’s article on The Register’s RegHardware ‘How to get your Wi-Fi working again‘, while making a nice and broad effort at examining the problems plaguing WiFi nowadays, and reviewing several options to improve your experience around WiFi, also uses somewhat pseudoscientific methods to measure things like signal strength.
Not that the N1 is a poor choice. Belkin’s software makes set-up a doddle and it’s handily compatible with both 802.11b and 802.11g for older, un-upgradeable devices. I hooked the N1 up to my cable modem, and was quickly up and running with the 802.11n USB adaptor plugged into my Vaio in the next room. Here, the signal registered as four blocks, two higher than the 802.11g RangeMax router yielded in the same location, albeit at a different time.
What exactly is four blocks? -60dBm? -110dBm? Cutting Tony some slack, he attempts to explain the issues and measurements in layman’s terms, so that as many people reading the article as possible will understand what he is talking about, but still, there are better ways to measure performance of WiFi networks. Signal strength readings are as reliable as my 90-year-old granny at the shooting range, save for a few cards which provide pretty accurate figures. A good measure of the performance, or lack thereof, in the various setups he studies, could have been net throughput. There are various tools to do this, such as the excellent yet very simple NetCPS from Netchain Communications. In WiFi, throughput is proportional (amongst other things) to available wireless bandwidth, that is, theoretical bandwidth minus artifacts such as interference and background noise – thus, between two particular machines, NetCPS would provide a good sense on how good a combination of routers, bands and adapters is performing.
You probably have seen the video on YouTube about a molten Fonera, apparently due to overheating, which shows the plastic case completely deformed. Gizmodo (also in spanish) and other sites are also reporting on this. As usual, Fon has censored the post on their forums that broke the story, but alas, thanks to their partners at Google, here is a cached version. Even Martin Varsavsky seems worried about this. It seems the damage is obviously from heat, but could it have come from the Fonera itself?
I, and others, have our doubts about wether this video is a fake stunt, or a true story. It is true that the Fonera overheats, much more than would be expected from a consumer-electronics product, but to the point of causing physical damage to the plastic case?
The heat problem
Heat in electronics mostly comes from dropping voltage by converting current into it, in our case, the voltage regulator in the Fonera drops 5V to 3.3V at 500mA, resulting in the dissipation of 850mW. That’s right, we are dumping 850mW right into the atmosphere in the form of heat. This brings the operating conditions very close to the maximum ratings for this regulator, which has a maximum rated thermal resistance of 90ÂºC/W, my calculations put the operating conditions at 88ÂºC/W. Additionally, the wireless section of the Fonera is also converting a lot of energy into heat.
After I finished my tests, I got a comment from Pobletewireless, regarding his own measurements of the heat problem, which are shown in very cool thermographs (no pun intended!) – much nicer than my rather rudimentary method.
I measured the temperature of the Fonera using a thermocouple connected to a Fluke 123 Scopemeter via an 80TK thermocouple module. The thermocouple was placed in between the heatsink and RF shield, the case closed, and the Fonera powered, as can be seen in this picture:
After 10 minutes operating normally, the temperature had risen to an average of 72ÂºC, with a peak of 80ÂºC.
The second batch of measurements were performed drilling four small holes to allow the thermocouple into the casing, the locations are shown in the following picture:
Maximum temperature at one corner was 43ÂºC. Next, an attempt was made to melt the white lid of the Fonera, by exposing it to a high temperature airflow from a paint-stripping gun, and at the same time, applying slight pressure from below. The thermocouple was used to measure at which point the plastic became maleable, and deformation started. At around 100ÂºC, the plastic was soft enough that a solid object could change its shape – this is in line with ABS plastic thermal properties, which state a deflection temperature around 100ÂºC, depending on specific material composition.
As the deflection point test resulted as expected, the lid was then exposed to an airflow at 280ÂºC for two minutes. The result of this exposure is shown in the pictures below:
It’s obvious that some deformation has taken place, with discoloration and charring on the point where heat was directly applied. However, the front side of the lid had mostly retained its shape.
The Fonera does indeed run very hot, much hotter than it should, if anything, for the good of the internal parts. Electronic components are sensitive to heat, with maximum ratings given by each manufacturer in terms of storage and operating conditions. The higher the temperature, the lower the service life of any given component. Some are affected more than others, most notably, electrolytic capacitors have a high sensitivity to heat, as it can evaporate the electrolyte quicker, causing it to fail. The capacitors in the Fonera are made by Taicon, a taiwanese manufacturer, and are max-rated for 105ÂºC. From the datasheet [PDF], at this temperature, the capacitor will fail after some 2000 hours, around 83 days. Following Arrhenius’ Law, and since the area around the capacitors was found to be at around 52ÂºC, their expected life would be 7800 hours, or about 325 days – what a coincidence, almost a full year, after which your warranty has expired. Comparing the Fonera to a Meraki Mini, one realises that there is a serious design flaw, as apart from the Mini having a switched-mode regulator, the wireless section shares exactly the same design as the Fonera. The temperature measured outside the casing of the wireless section indicates that the junction temperature of the components inside has to be ridiculously high. So, one conclusion is that the Foneras will eventually fail due to overheating, and it will probably happen sooner than later.
On the deformation / melting video – in my opinion, it’s not real. At least, it couldn’t have happened without the Fonera reaching temperatures around the whole casing that would have caused some components to blow up (for example, the capacitors). The Fonera could not have undergone such an extreme temperature, and still function as shown on the video. The temperature gradient between the heatsink and one corner of the case is almost 2:1, thus, to reach a deformation temperature of say 200ÂºC at the corner, the heatsink must have been running at 400ÂºC! A final bit of evidence – the sticker. If you look closely at the video, the sticker on the bottom of the Fonera looks almost unscathed. Here is a picture of what it looks like after applying a 250ÂºC airflow for 30 seconds, which causes the plastic to deform:
Obviously, a more prolongued exposure would have damaged it even more. In all honesty, I would love to get more details from the guy who made the video, as it stands right now, I’d call it a hoax.
I got a tip today that Fon is looking at launching a new router with a LAN port, apart from the WAN port found in the current Fonera (they seem to privately admit not having a LAN passthrough was a rather big mistake).
With the current Fonera, you cannot access devices on the wired side of the network (such as a SAN drive or printer) from the wireless side, be it using the public or private SSID, you are effectively NATted from your own network. A LAN port would solve this the same way as it is done in higher quality devices such as the Linksys WRT54 series.
What really surprised me was to see that these routers have already been shown by Accton, the OEM that manufactures the Fonera on their website for a few weeks. Check out these links, datasheets in PDF available, for a white-label Fonera, a Fonera with LAN passthrough, and what looks to be the Fon Liberator, having a USB port and BitTorrent client built-in! Martin Varsavsky recently put the release date of the Liberator back a few months, originally scheduled for Christmas 2006, citing technical difficulties.
Now, either Accton wants to score a goal taking advantage of the publicity offered by Fon, or Fon didn’t pay an exclusivity fee for the design of these routers, or both. One million routers by 2010 is nothing by asian manufacturer standards, but they do allow buyers to secure exclusive designs. Copies could still be found, but not as prominently and by the same manufacturer making their own.
I wasn’t sure that Accton was the designer behind the Fonera, and gave Fon the benefit of the doubt of actually having developed something themselves in the electronics field, but now it seems clear that Accton is the designer of the hardware platfom, so there wasn’t that much development by Fon after all (the firmware was created by the hackers behind DD-WRT and OpenWRT).