one constrained client and multi-server with the same resource type conmunication problem

Hello there!

I have 10 light devices, each device as a server  has a light resource .

and all the resource type are the same ,like "oic.r.light", and the URI is "light/1" to "light/10". 

how can the constrained client discovery all the 10 devices in the same time ?

And how to get the resource list?

can you guys help to solve this problem?

Thanks!