Signal bars - What are they for?

There's an icon in the corner of every mobile phone's screen that we are all familiar with. But do we really know what those signal bars mean?

That question was raised for me by this blogger, who also links to an interesting discussion thread on the matter here. Various people pitch in, some with knowledge of working in the handset or network operator industry. They give a suite of reasons that the bars are not much use, including:

• There are no industry standards for what 'one bar', 'two bars', etc means
• Some phones estimate signal quality when idle, only measuring it properly when you try to call, which is misleading
• Under the CDMA protocol used in North America, bar represent signal strength, but not a variable dubbed EC/I0, which is the portion of that signal that is usable

Interesting points. But if we want to improve things, the technical details are not really important. We need to decide what we want to know about our signal first.

At the moment, phone manufacturers give us little idea of what to expect. But people still read a lot of information into signal bars. It's not unusual to hear people boast "I've got five bars" when a friend struggles to connect. I often hear people comparing signal strength on parts of London's metro network where the tunnels are not deep enough to completely block signals.

But really, most of us have no idea what those bars mean. I think we need to rethink them, with an indicator directly related to what you can do with the signal you have.

How about using these four categories:

• No signal
• Text messaging only
• Poor call quality likely
• No problems

I'll admit that's not perfect. For example, an indication of how much bandwidth you have for data transfer could be useful. Can anyone else think of a better way of representing signal strength and what you can do with it?

[via newscientist]