Now, we use an example to show the advantage of MRIL over the existing mesh routing schemes.
Before presenting MRIL in detail, we introduce some terminologies as follows.
In MRIL, every node keeps a 2-dimension table, called extended neighbor list (EN-List), to maintain the information of the nodes at most r hops apart.
Frame Formats of Command Frames Used in MRIL. To support MRIL, we introduce the command frames OHHello, RCAgentAnnouncement, and MRILHello.
Selecting ARC in MRIL. In the association stage, when a node receives more than one association reply, it selects the node with the smallest tree level as its parent, which makes SL chains longer.
In MRIL, we use the ARC indicator (ARCI) function in (1) to indicate that a node becomes an ARC of an RC, which reflects the fact that an ARC should be with fewer children, more remaining energy, and better link quality than its SLNBs:
Routing Procedure in MRIL. The routing procedure of MRIL is as follows.
We compare the proposed MRIL with the IEEE 802.15.5 mesh routing (the basic mesh routing for short) in terms of energy consumption, number of transmissions for maintaining LS information, and memory usage through simulations.
First, we compare MRIL with the basic mesh routing in terms of the sizes of connectivity matrix and extended neighbor list, which are shown in Figures 10-11.
It can be seen from Figure 12 that MRIL delivers packets with less hops than both the basic mesh routing and the traditional tree-based routing.
The numbers of transmissions needed for the nodes to maintain LS information under MRIL and the basic mesh routing are compared in Figure 16, which reveals that MRIL has less overhead in maintaining LS information than the basic mesh routing.
Third, we compare the MRIL with the tree-based routing in terms of the number of packet transmissions.