PDMAC: A Priority-Based Enhanced TDMA Protocol for Warning Message Dissemination in VANETs

. 2019 Dec 19;20(1):45. doi: 10.3390/s20010045

Algorithm 1 Clock synchronization.

Input:N,

\bar{C H}

, and C
Output: Synchronized time for all CHs and member nodes
Begin:
Set N[

v a l i d a t e_t i m e r

] as OFF

Inter-cluster Clock Synchronization:

C H_{B}

⟵ Rand(

\bar{C H}

)
Set

C H_{B}

[

v a l i d a t e_t i m e r

] as ON

C H_{B}

broadcasts

S y n c_{C H}

For i = 1 To sizeof(

\bar{C H}

)
If

C H_{i}

[

v a l i d a t e_t i m e r

] = OFF Then

T_{C H_{i}}

⟵

T_{C H_{B}}

Set

C H_{i}

[

v a l i d a t e_t i m e r

] as ON
                      Else
                          No clock synchronization is required
                      End If
               End For

     Intra-cluster Clock Synchronization:
        For j = 1 To sizeof(

\bar{C H}

)

C H_{j}

multicasts

S y n c_{M E M}

to its member nodes
For i = 1 To sizeof(C)

C_{i}

sends

a c k_{i}

C H_{j}

C_{i}

[

v a l i d a t e_t i m e r

] = OFF Then

T_{C_{i}}

⟵

T_{C H_{j}}

Set

C_{i}

[

v a l i d a t e_t i m e r

] as ON
                      Else
                          No clock synchronization is required
                      End If
               End For
        End For

End