## 4 Comparison and Discussion
### MAC Approach  
In an interference scenario, the DCM algorithm [25] first detects collisions between beacons or data so that the WBASN can evaluate the degradation of performance before switching the channel. Each WBASN's coordinator must perform the channel scanning and data retransmission. This is an advantage of DCM, because WBASNs manage their own working status independently. Another advantage is the low latency of the data frame. However, this does not guarantee that the QoS requirement is met. Although the likelihood of successful transmission is high, the high power consumption of WBASNs may lead to increased temperatures of the sensors in WBASNs. Unlike DCM, InterACS applies only the switching channel into WBASNs to mitigate interference without considering packet loss. In InterACS [26], the framework for interference records the node's activity and status, and the coordinator selects the channel based on the current SIR value to avoid collision. Although this algorithm is simple and standard, it ensures inter-WBASN interference. However, the simulation in [26] was run with low-density WBASNs. Therefore, it is necessary to investigate the performance of InterACS in a high-density WBASN scenario. Moreover, InterACS does not consider a dynamic interference scenario, which will be faced in any real-world setting. Some requirements to consider are the power consumption, QoS constraint, mobility support, and end-to-end delay. It has been shown by experimentation that the transmission efficiency of the lightweight and robust interference mitigation scheme (LRIM) [27] is suitable for application. As with InterACS [26], LRIM applies channel hopping to avoid interference. However, LRIM is more effective than InterACS because of channel sensing. Because LRIM employs a node as a watcher, the efficiency of channel sensing is high without affecting the performance of the whole network. Nevertheless, the mobility of WBASNs and the QoS constraint are not considered. Moreover, the end-to-end delay may be high because of the channel sensing and switching tasks. The DRA scheme [28] considers the interfering nodes for rescheduling transmissions among WBASNs. Each WBASN within the interference range generates its own table of interfering nodes in every WBASN. WBASNs must negotiate before reallocating their time slots based on the knowledge of inter-network interference. DRA increases spatial reuse compared to conventional orthogonal channel assignment. This scheme, which investigates the shadowing effect and threshold value of the SINR, aims to ensure high performance of DRA with regard to the fading effect caused by human mobility. However, WBASN requires a low SINR threshold and must update its information upon every change in the network based on SINR. The convergence time depends on the broadcast at each round. Therefore, a correct decision between SINR and spatial reuse must be reached. In the service-based scheduling scheme [29], the QoS requirement of traffic is the primary factor of concern regarding the allocation of data to the superframe in an interference scenario. The superframe is defined in IEEE 802.15.6 [1] and is used with beacon mode. Therefore, WBASNs with higher priority can transmit data in a collision scenario while the others suspend their transmissions. Moreover, the power consumption is not affected because the packets do not collide. The disadvantage of this scheduling scheme is that it does not consider dynamic environments, changing topology, or high-density WBASNs. The end-to-end delay is high for WBASNs in listening mode whereas the end-to-end delay is low for high-priority WBASNs. The AIIA scheme in [30] also updates information by using a table. The AIIA table contains information about the location of the contention-free period in the superframe of neighboring WBASNs. The AIIA learns about the timing offsets between its timer and a neighboring GW's timer through the coordinator and, then a TDMA transmission schedule is designated for neighboring WBASNs.