Relays may be used in LTE-A to enhance coverage and capacity and offer more flexible deployment options. A relay node (RN) may create new cells, distinguishable and separate from the cells of a donor-evolved NodeB (eNB), where the donor-eNB may support a Un interface to support eNB to RN communication. To any legacy wireless transmit/receive unit (WTRU), an RN may appear as an eNB. That is, the presence of an RN in its communication path to the donor-eNB may be transparent to the WTRU. An RN may be an eNB that has a wireless in-band backhaul link back to the donor-eNB by using an LTE or LTE-A air interface within the International Mobile Telecommunications (IMT) spectrum allocation.
A two-way communications system with two transceivers and one relay node may take four time slots to complete a message exchange, assuming time division duplex (TDD) half duplex mode and no direct link between two transceivers. It would be desirable to have a method and apparatus for implementing a relay scheme that may use a lower number of time slots and may also have a low level of complexity.