Busy Lamp Fields

Many DECT phones are using in small companies, where the users still are in love with their good old analog phone systems. One of the features that users love so much is the busy lamp field and the shared line appearance. Would it make sense to have such a feature on a business DECT phone as well?

The idea goes like this: Why don’t we add a few (e.g. four) buttons below the display and use a LED behind them to show the status of other extensions? Then the software can subscribe to the button information, and when the PBX has an update, the DECT base would operate them. When used as shared line buttons, these buttons could be used for seizing an outbound line, placing a call, parking or holding a call and then when blinking picking it up on another handset. It all works nicely on the snom desktop phones (when using snom ONE), so it would make sense to have it also on the handset.

Well, there are a few obstacles. First of all, adding buttons means changing the plastic; changing the hardware. This is something that you don’t want to do, if you don’t have to.

Then there are problems on the DECT side. The way DECT works is that the handset sits there and waits for broadcast messages every few seconds. Then the handset could setup a connection to the base and fetch the message from the base (DECT still pretty much comes from the TDM world, so there is no big difference between a phone call and a data connection). When the LED are changing frequently, that would mean a lot of connections; and each of them takes power. The other little problem is that most DECT stacks have problems with more than one connection at a time, which would be another obstacle when you are in a phone call to update the LED. And especially if you want to support a large range of DECT handsets, you might end up in a lot of connections, making it difficult to have some space left for the voice!

So the bottom line is: Everything is possible, but some things are just easier than others. As for the BLF idea, this belongs to the ideas which are more difficult. There is a reason why there is no DECT device in the market with this.