The only difference between the first two slots is that the first slot is for relays with source-to-relay rate of 2 Mbps and relay-to-destination rate of 5 Mbps, whereas, it is reversed in the second slot.
The second method is preferred for several reasons: the record in the failed relay may be affected by the failure of the device itself or a component of the fault clearing system – for example instrument transformers or the wiring between them and the relay the sampling rate of the recording by the relay may be too low which will not correctly represent the abnormal system condition.
For instance, the first two slots are for contention among relays with each relay having a combined rate of 1.46 Mbps (, see [4, 5] for details).
In the above differential equations, dI/dt is the variable rate of relay nodes which have carried the duplicated packets.
Since the DF protocol is employed in the relay node, the ergodic rate of the whole system is determined by the minimum rate during the broadcast phase and the multiple-access channel (MAC) phase as in Theorem 1.
Except for the power allocation, the effect of the relay selection is illustrated in Fig. 3 a, c for the relay-assisted networks (e.g., the cognitive OWT-RA and TWT-RA networks), which shows that with relay selection, the achievable rate of the SU can be greatly improved.
The two parts are sent independently, and the rate can be expressed as the sum of the rates of the source-destination channel and the two-hop source-relay-destination channel (the rate of the later is constrained by the source-relay link).
In [11], the authors investigated the bit error rate of single-relay AF relaying over lognormal channels.
As we can see later, the extension of [9] to two relays results in a rate of 1/3.
We can see that as the number of relays increases, the sum rate of users increases more obviously under the proposed algorithm.
For the DF scheme without a diversity protocol, the instantaneous transmission rate of relay-mobile pair (k, m) at subcarrier n can be written as [1] c km, DF = 1 2 log ( 1 + SNR km, DF n ) = 1 2 log ( 1 + min { P s, km n a k n, P r, km n b km n } ).
