In this paper, we propose an interference alignment (IA) scheme for the multiple-input multiple-output (MIMO) uplink cellular network with the help of a relay which operates in half-duplex mode. The proposed scheme only requires global channel state information (CSI) knowledge at the relay, with no transmitter beamforming and time extension at the user equipment (UE), which differs from conventional IA schemes for cellular networks. We derive the feasibility condition of the proposed scheme for the general cellular network configuration and analyze the degrees-of-freedom (DoF) performance of the proposed IA scheme while providing a closed-form beamformer design at the relay. Extensions of the proposed scheme to downlink and full-duplex cellular networks are also proposed in this paper. The DoF performance of the proposed scheme is compared to those of linear IA scheme and relay-aided interference management scheme for a cellular network with no time extension. It is also shown that advantages similar to those in the uplink case can be obtained for the downlink case through the duality of a relay-aided interfering multiple-access channel (IMAC) and an interfering broadcast channel (IBC). Furthermore, the proposed scheme for a full-duplex cellular network is shown to have advantages identical to those of a number of proposed half-duplex cellular cases.

As Korea's Standards Organization, TTA had published the common platform standard for Smart TV based on HTML5 web runtime environment to support any application's running on various smart TV devices with the same user experiences. Among various technical features of the standard, this paper introduces multiscreen technology that a mobile device can interact with an application running on smart TV platform. Smart TV and mobile device can discover each other, create service session using WebSocket and communicate each other through specific messages based on smart TV platform specification. This paper also explains conformance testing environments. To guarantee OSMU(one source multi use) of multiscreen application for smart TV devices, TTA had published conformance testing specification separately according with smart TV platform standard and established testing environments including various test cases, test framework, test equipment and so on. This paper explains TTA conformance testing environments for multiscreen service in detail and shows the result of implementation and experiment with the real multiscreen service example.