Design and investigation of scalable multicast recursive protocols for wired and wireless ad hoc networks

the source is N2 where it is already a BNR, and will update its MFT table entry to add
x’LMR (M3), and unset the S bit in the request message. The request message R_qM₀(11)
sent to the source to complete the joining process. As mentioned before this message will
arrive in short time to the source because the S bit is set to 0 on the first BNR (N2). The
source upon receiving this registration message sends back a confirmation message
R_pM₁(00) towards the first BNR(N2) on behalf of x’LMR(M3) request message. At the end
of this procedure the new receiver (x) will be considered as a member in the multicast group.

Again, it is worth to notice that there are no changes in the multicast tree construction

because of this new joining receiver.

Figure 4.7 Joining process in SReM (Case 2)

■ Case 3:

In this case, the new receiver (x) is the first receiver joining LMR and there is intermediate
IMR(s) in the path to the first BNR towards the source. Figure 4.8 shows this case, where the
new receiver (x) that wants to join the multicast group sends a JoinM message to the
designated LMR (M3). Upon receiving this message, M3 will create and send a R_qM₁(11)
towards the source. The IMRs along the route to the source just forward this message without
any changes. Upon receiving this message, N2 as the first BNR along the route to the source
updates its MFT entry by adding the x’LMR. Moreover, N1 will update the request message

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