How can I build Wireless sensor network using nRF51422

[Alok]

I have about 200-300 sensors, each requiring to send data at around 0.5-1Kbps to a central node (coordinator/master node), what will be the network configuration/topology using nRF51422 (or any other better suited Nordic IC) to send the data of all the sensors to the central node?

[ovrebekk]

Using the micro ESB library means you don't have to configure the radio registers directly, and you don't have to write your own code to handle packet buffering, acknowledgements, re-transmissions and so forth. The micro ESB library also provides an API similar to the NRF HAL API for the older nRF24L series, so it is easier to use if you have experience with the older Nordic radios.

[Alok]

Thanks, what kind of typologies (star/tree/mesh) can be supported using proprietary radio, and what is the max number of nodes that the network will be able to support. How can central node send beacons on multiple preconfigured nodes (I assume the beacon is not sent simultaneously on multiple channels, rather it is sent serially, other wise multiple radios are required ?) and if the sensor can respond with data on either of these channels, the central node should be configured to receive the data on all the channels, which will again mean that central node needs to have multiple radios, listen simultaneously, or I may be missing something.

[ovrebekk]

In the proprietary mode there are very few limitations. You can do any type of network topology, and in theory you can support as many nodes as the 40-bit address allows (within reason of course, the available bandwidth and number of channels limit how many nodes can communicate simultaneously).

It is true that a single radio can only transmit or receive on one frequency at the time. The beacon device will typically have to dedicate timeslots to the different channels. For instance you can send a beacon on channel 1, switch to receive and receive packets from all the nodes on channel 1. Then you switch to channel 2, send a beacon, receive packets, switch to channel 3 and so forth... As long as the interval between each beacon remains fixed the sensor nodes will know that if they miss the beacon on one channel they can switch to the next channel in the list and try to get that beacon.

[Alok]

For Mesh networking, support of routing function is required as in Zigbee, is this implemented in the micro ESB library if proprietary radio is used? Thanks.

[ovrebekk]

There is no higher level mesh functionality in the micro ESB library, no. This would have to be implemented in the application.