One of the key enhancements for BLE in v4.1 is the added support for a slave device to be able to connect to TWO master devices, i.e., the slave device can simultaneously belong to two star networks. This was not allowed in v4.0 specification.
A slave device can also act as a bridge between two star networks. However, this is not explicitly covered in v4.1 of the spec. The topic of a slave devices to act as a bridge between two star networks and the master-slave role-switching are expected to be resolved in future versions of the specification.
