Posts tagged iOS

How to Switch from Bars to Numerical Signal Level on iOS without Jailbreaking

I’ve made a habit of only ever looking at signal level in numerics on iOS since the iPhone 3GS days. This has paid off a few times in the past (notably the iPhone 4 antenna situation) but in general just gives a better perspective for network conditions. I regularly post screenshots with both cellular and WiFi in numerics instead of the default bars, and on iOS this is pretty simple to make happen, at least to the cellular signal level indicator, without jailbreaking.

To do this the basic workflow is to enter FieldTest.app, then force quit the application. When FieldTest launches, it changes a .plist file for springboard which controls whether numerics are being shown for cellular signal. This is exactly the file that SBSettings tweaks if you’re toggling “Numeric GSM” and “Numeric WiFi.” I should note that these settings also stay around across iOS restores. Anyhow a lot of people have been asking on Twitter lately for some reason how to make this happen, so I thought I’d write it up.

  
Dialer for FieldTest (left), FieldTest.app (right)

Anyhow to show cellular signal without using SBSettings:

  1. Launch FieldTest.app by going into the dialer and dialing *3001#12345#*
  2. Hold down standby/lock like you’re going to turn the phone off
  3. Release standby/lock after the power off slider appears, then hold home (this is force quit on iOS – it’s impressive so few people know it)
  4. Boom, you have numerics instead of bars

This can now be tapped to switch back and forth. Launching FieldTest again and quitting will restore the file however, so every time you quit this will have to be a force quit to preserve the setting without jailbreaking or restoring an iOS backup with the plist file set how you want it.

I should also note that on LTE this number is RSRP (Reference Signal Received Power) in units of dBm. On WCDMA this is RSCP (Received Signal Code Power) in dBm, and on CDMA2000 1x/EVDO this is RSSI I believe (or EC, I haven’t ever carried a CDMA2000 iPhone for an apreciable amount of time). On WCDMA and 1x/EVDO values between -50 and -113 dBm are typical, with -50 being at cell center and -113 dBm being at cell edge. On LTE because the iDevice is showing RSRP, values between -75 and -120 dBm are typical, with RSRP showing ~20 dB lower than the analogous RSCP/WCDMA-land signal if you’re trying to compare.

Update/Note: In iOS 7 the signal bars were changed to dots, but the trick still works. Although switching into numerals by force quitting Field Test still works, sometimes it takes a few tries before it works. I’m not sure why that is, but keep force quitting or try quitting and coming back and force quitting again and eventually you’ll switch over.

Spoiled by iMessage – Or Things I don’t miss about SMS

As the smartphone space becomes increasingly commoditized, the obvious next step is to make hardware choice a function of ecosystem choice. That’s already happened for some of the obvious features (marketplaces for music, video, and books), but the next step is delivering ecosystem-specific features for core phone functionality. Probably one of the features I use the most on a device is messaging, and since iMessage is nearly a year old, I couldn’t help but think more about why I feel a back-of-my-mind longing for it whenever I go back to a device that’s strictly SMS. Also, a recent influx of weird SMS issues I encountered while chatting with a friend prompted both a twitter rant and me deciding to finally get all of this down somewhere.

So here’s a simple bulleted list about some of the things I don’t miss about SMS:

  • Split messages at the 160 character limit
    • The caveat here is that some carriers do indeed properly concatenate messages, but this usually only works if both sender and recipient are on the same carrier. The Verizon -> AT&T exchange used to properly implement this, back when the CDMA iPhone 4 came out, but it later was broken and inexplicably never fixed. Part of me wonders whether iMessage wasn’t spawned partially because of this annoyance.
  • Messages arriving out of order, sometimes as a result of the split from the character limit
    • This is a continual annoyance, there’s no greater way to break the flow of a conversation than by having replies arrive completely out of order. Also SMS is predominantly circuit switched, and not an IP based protocol. Obviously BBM/iMessage just work over the internet, and aren’t tied to having a working cellular session.
  • No delivery guarantee, SMS is best effort delivery only
  • Duplicate SMSes as a result of carriers implementing proprietary systems to mitigate SMS’ best effort delivery system
    • Verizon seems to be particularly aggressive about this. I still would like to know more about just how their system determines when to re-send a particular SMS, but I sometimes get 3 or 4 of the same SMS from Verizon subs.
  • No read reports or delivery status reports (at least on most new smartphone OSes that don’t implement SMS delivery receipts)
    • Delivery reports are actually a pretty common feature for SMS (usually just uses a prefix), but implementation varies from carrier to carrier and is a big mess. I suspect this is the reason smartphone platforms tend to implement it at random, if at all.
  • Delivery time is sometimes very long depending on SMSC load
    • Try getting an SMS delivered on New Years, I dare you.
  • Image sizes are smaller and more compressed for MMS, different for each carrier and up to the exchange to accommodate and tailor to sizes
    • This is set on iOS in the carrier bundle
    • iMessage can deliver full quality images if both sender and recipient are on WiFi
  • The price of an SMS
    • $0.11 per message is downright absurd

RIM understood the importance of having a platform-specific messaging product with BBM, specifically in both the platform lock-in and loyalty that this kind of feature adds. There’s a certain amount of potential energy that it takes to overcome both this messaging tie-in when switching platforms, and users can readily identify the differences. Apple clearly got this and delivered with iMessage, and I expect that having a messaging platform that spans the smartphone, tablet, and desktop will make that potential energy to escape to another ecosystem even harder to overcome. There’s a certain message or conversational velocity that makes BBM and iMessage feel entirely different from traditional IM, yet faster than the sometimes minute-delayed SMS.

Currently Google’s messaging “product” is Google Chat, but the acquisition of Meebo and other internal rumblings make me strongly suspect that a more cohesive and mobile-oriented messaging product with the same BBM/iMessage like conversational velocity is coming, maybe even at Google I/O 2012. There’s so much at work here which both shifts the balance of power away from the carriers and also makes the whole messaging experience better by sharing it with the tablet and desktop.