The protocol Zigbee is based on IEEE 802.15.4 standard. The choice of this protocol was taken relatively to various criteria.
First, IEEE 802.15.4 offers data rates at 250kb/s at ISM (Industrial, Scientific and Medical) 2.4GHz band which satisfies healthy environment conditions and acceptable rates. Second, Zigbee is characterized by its scalability, which perfectly responds to the high number of communicating modules in the hospital scenario. Besides, this technology is known with its battery autonomy (years), hence reducing the maintenance cost of the platform. And finally, its coverage (up to 10-20m) is sufficient to let patients freely moving under continuous supervision.