Taxonomy and Evaluations of Low-Power Listening Protocols for Machine-to-Machine Networks

Table 1

LPL MAC protocols.

Protocol	Features
B-MAC [6]	(i) Berkeley MAC; (ii) LPL with check time, back-off window size, and power-down policy in the application level; (iii) Advanced clear channel assessment (CCA) for dealing with random noise
Wise-MAC [7]	(i) Improved LPL, remembering neighbors’ polling schedules; (ii) Sends short preamble when the receiver wakes up
X-MAC [8]	(i) Upgraded B-MAC protocol; (ii) Divides long preamble into two parts (micropreamble/receiver address) to solve overhearing
SpeckMAC [9]	(i) Consists of SpeckMAC-B, SpeckMAC-D; (ii) Consecutive data frame, wake-up packet; (iii) Sender accesses receiver with 3 bytes preamble in the packet frame
RI-MAC [10]	(i) Receiver-initiated MAC protocol; (ii) Receiver sends periodic beacon frame and sender sends data frame if beacon frame is received
BoX-MAC [11]	(i) Cross-layer MAC protocol using PHY, link layer; (ii) Consists of two parts (BoX-MAC-1/BoX-MAC-2); (iii) Goes into sleep state in back-off time; (iv) Less wake-up time than X-MAC
MX-MAC [12]	(i) An LPL variant of CSMA-MPS; (ii) Compatible with X-MAC and SpeckMAC; (iii) Consecutive packet transmission instead of short preamble strobe in X-MAC; (iv) Sends ACK when packet is received to solve X-MAC’s early ACK problem
A-MAC [13]	(i) Receiver-initiated MAC protocol; (ii) Using hardware-generated acknowledgment (HACK) for more efficient energy consumption; (iii) Saves neighbors’ LPL schedules; (iv) Deals with hidden terminal problem