# Optimization of the AODV-Based Packet Forwarding Mechanism for BLE Mesh Networks
## 3 Related Works  
In order to identify the research gap, we reviewed the latest BLE-based mesh communication protocols.  
The early BLE mesh solution proposed by [16] is called MultiHop Transfer Service (MHTS). The proposed solution also works well for the two-hop and three-hop transmission of data. [PERSON] [17] used the available mesh protocol to construct the mesh topology on office doorbells. According to [18], it is possible to support long-range communication due to the incorporation of the scattenet topology in Bluetooth 4.1. The author introduced the concept of service mediation based on Name Data Networking (NDN). In addition, BLE multihop routing was developed by [19], based on a scatternet topology feature of the BLE 4.1 protocol. To increase production, [PERSON] [20] developed a BLE-based data collection approach for the agriculture area. Moreover, [PERSON] [21] proposed the design for a multihop tree-based wireless network implementation, Furthermore, [PERSON] [22] proposed a dynamic node organization approach for data routing, through an on-demand routing technique. In order to allow mesh functionality in an existing BLE beacon network, [PERSON] [23] presented a novel BLE-based overlay mesh that addresses issues related to the best-effort scheduling and RSSI- based bounded flooding. Likewise, References [9; 24] gave performance measures using the existing protocols, i.e., trickle and FruityMesh. Subsequently, a directional ad hoc on-demand multipath distance vector technique was proposed by [25]. By providing a directional link quality indicator for the routing schemes, the protocol overcame the problem of moving nodes' transmission instability. Furthermore, Reference [26] developed a BLE protocol to unravel the weaknesses in the BLE specifications on industrial wireless sensors networks. The main idea behind the article was to divide a network into different subnetworks that were each controlled by a master. To tackle the problem of overlapping events and enable real-time communication, Reference [27] suggested a BLE-based real-time multihop communication network with bounded message delays. Moreover, Reference [28] introduced BLE's multihop on-demand routing protocol, proposing topology configuration and recovery procedures. Reference [29] talked about using BLE technology to automate parking systems. Reference [30] also worked on a specific relay distribution in a flooding-based BLE mesh network with collision mitigation to increase the overall PDR. Moreover, an AODV-routing-based BLE mesh protocol was proposed by [6]. According to the author, less traffic was generated by the protocol than the mesh.  
The aforementioned works attempted to improve the BLE mesh protocol features, as well as experimented on the available BLE mesh protocol, but did not focus on improving the underlying protocol. Only [6] has worked on a routing-based protocol to improve the performance of the packet-forwarding mechanism. As a result of the preceding, in this paper, we focused on improving the protocol proposed by [6] by reducing overheads, retransmissions, and delays. Moreover, the selected protocols mentioned in this section are summarized in Table 1.  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Ref.**} & \multirow{2}{*}{**Ref.**} & \multirow{2}{*}{**Ref.**} & \multirow{2}{*}{**Ref.**} & \multirow{2}{*}{**Ref.**} & \multirow{2}{*}{**Ref.**} & \multirow{2}{*}{**Ref.**} & \multirow{2}{*}{**Ref.**} & \multirow{2}{*}{**Ref.**} & \multirow{2}{*}{**Ref.**} \\  & & & & & & & & & \\  & & & & & & & & & & \\  & & & & & &