\In a packet voice communications system, a source transmits a packet containing digitized speech to a receiver. Because transmission errors occasionally occur, an acknowledgement (ACK) or a negative acknowledgement (NAK) is transmitted back to the source to indicate the status of each received packet. When the Voice packets are delay sensitive, and a packet can be transmitted a maximum of d times. If a packet transmission is an independent Bernoulli trial with success probability p, what the PMF of T, the number of times a packet is transmitted?