ABSTRACT
As described in Chapter 2, a wireless sensor node owns limited resources, such as power, bandwidth, computing capability, and storage space, which must be taken into account when devising MAC protocols in WSNs. Energy is a key concern in battery-powered sensor nodes. Once the battery is consumed, it is generally diffi cult or impractical to charge/replace exhausted batteries. Th at is why, the primary objective in many WSN MAC protocol designs is maximizing node/network lifetime,
leaving the other performance metrics a s s econdary objectives. For example, t he energy could be saved by turning off the devices that are not in use at the particular period of time.
