## 2 Related Work  
Table 1 summarises the previous works made for trying to contain the overhead that traditional flooding generates. All protocols listed share a standard behavior; they chase the original flooding once the target node is found, attempting to stop further propagation of flooded packets in the rest of the network. Repeal-based protocols can be divided according to the entity that initiates the chase flooding into Broadcast-Repealing-Initiated in Source (BRIS) or Broadcast-Repealing-Initiated in the Destination (BRID). These protocols can also be divided into bounded, if the chase packet is bounded to an area (usually defined by a TTL), and unbounded if the chase packet can go along the whole network. Also, the protocols use different broadcasting speeds to allow the chase of the flooding messages. Such speed usually depends on the time required to transmit a packet \(\delta\), and the number of hops between the source and the retransmitting node \(d\). Another distinctive feature of these protocols is the propagation strategy used during the initial and chase floodings. For example, protocols can use different propagation speeds for the initial and chase floodings, delay packets during the initial flooding so they can be reached by chasing packets, or might use one speed inside a ring and a different one outside the ring. Figure 1: Behavior of Flood and Contain (F&C) vs. other schemes. In L-B [9], the authors introduced the first attempt to contain the propagation of flooded packets by chasing the Resource Request (RQ) packets after the source node received a Resource Reply (RP) packet. The L-B protocol relies on different speeds for transmitting the RQ and the chase packet, with the chase packet speed being faster. In LHBA [11], they improved the chasing time by starting the chase in the destination rather than in the source. BERS [12] proposed a ring-search mechanism to reduce the energy consumption of TTL-Expanding Ring Search widely used by some reactive routing protocols. This mechanism was improved by BERS+ [13], where the ring expands without the need of retransmitting the original RQ from the source, but it resumes the expansion from the last ring. An update was performed in BERS* [15] by halving the waiting time in each ring, thus speeding up the route discovery. In [17], the chase stage occurs in the receiver rather than in the source node as performed earlier. In [14], the authors used the ring as a boundary to retransmit the RQ at two different speeds. Inside the ring, the RQ travels at speed \(s_{1}\) while out of it, it travels at speed \(s_{2}\) where \(s_{1}>s_{2}\). AODV-PC [16] improved [14] by starting the chasing in the receiver. ABC [20] retransmits the RQ only to areas where it is more probable to find the destination node to prevent arbitrary flooding. This scheme has the disadvantage that it needs some previous information about routes, as well as topological information. A clustered version that combines BERS+ and MPR is presented in [21], where the authors reduced the number of broadcasts by selecting appropriate cluster heads. Unbounded protocols (L-R, BERS+, TLRDA-C, AODV-PCABC, CMBERS+) do not establish a limit or boundary for the chase packets to contain the original flooding. As a result, these protocols can easily transmit more packets than traditional flooding alone. This behavior occurs when the distance between the source and destination is equal to or greater than the network radius, which is a frequent event. Bounded protocols (ERS, LHBA, BERS, BERS*, tBERS, BCIR, I-BERS) try to avoid the previous drawback by placing a ring-boundary defined by the source-destination hop count beyond which no chase packets can cross. However, the performance of bounded and unbounded protocols might not always be what their authors expected.