Gazell OR BLE Multilink Central?

[Punit]

I have gone through the SDK and from what i basically understand is that gazell and BLE Multilink look very similar from the application point of view(1 Host connecting to 8 devices).

Can anyone please tell what is the exact difference btwn the two.I have just begun exploring BLE for using it in a project and my application requires me to use multiple peripherals with a Central device...

[Hung Bui]

Hi Punit,

You are correct, they are pretty similar especially on the topology which is star topology and one host can support up to 8 client and they both use ISM band for RF communication. Note that BLE by theory can support more than 8 client, but with our softdevice we only support up to 8 peripheral (S120).

However, they are pretty different on the protocol. You can find that with Gazell, the host simply listen and the client starts the transmission. On the other side, with BLE, the central starts the transmission. All upper layers, packet format are also different.

And most important, BLE is the standard protocol defined by Bluetooth SIG (which Nordic is part of) and is supported by most current smartphone/tablet/PC.

When Gazel is our proprietary protocol that we defined. It's provided as part of our SDK.

So in short, if you want your device to be able to interface with phone/tablet/PC you should use BLE. If you don't care about that you can use Gazel (or BLE)

[abc]

If you don't need BLE, is there ever an advantage to using it over a proprietary protocol (e.g. ESB, Gazell) beyond code re-use?

[Anders Strand]

In BLE, the devices must be connected in order to communicate. In Gazell and ESB, this is not needed. So for example you can have devices moving seamlessly in and out of the network. They are also much simpler protocols, where you have more control over what happens when.