Showing papers by "Rapeepat Ratasuk published in 2013"

Modeling, Analysis and Optimization of Multicast Device-to-Device Transmission

Abstract: Multicast device-to-device (D2D) transmission is important for applications like local file transfer in commercial networks and is also a required feature in public safety networks. In this paper we propose a tractable baseline multicast D2D model, and use it to analyze important multicast metrics like the coverage probability, mean number of covered receivers and throughput. In addition, we examine how the multicast performance would be affected by certain factors like mobility and network assistance. Take the mean number of covered receivers as an example. We find that simple repetitive transmissions help but the gain quickly diminishes as the repetition time increases. Meanwhile, mobility and network assistance (i.e. allowing the network to relay the multicast signals) can help cover more receivers. We also explore how to optimize multicasting, e.g. by choosing the optimal multicast rate and the optimal number of retransmission times.

An Overview on 3GPP Device-to-Device Proximity Services

Abstract: Device-to-device (D2D) communication will likely be added to LTE in 3GPP Release 12. In principle, exploiting direct communication between nearby mobile devices will improve spectrum utilization, overall throughput, and energy consumption, while enabling new peer-to-peer and location-based applications and services. D2D-enabled LTE devices can also become competitive for fallback public safety networks, that must function when cellular networks are not available, or fail. Introducing D2D poses many challenges and risks to the long-standing cellular architecture, which is centered around the base station. We provide an overview on D2D standardization activities in 3GPP, identify outstanding technical challenges, draw lessons from initial evaluation studies, and summarize "best practices" in the design of a D2D-enabled air interface for LTE-based cellular networks.

Millimeterwave access architecture with rapid rerouting

Abstract: In accordance with the exemplary embodiments of the invention there is provided at least a method and apparatus to determine information comprising a direction and a strength of signaling associated with a mobile apparatus, where the apparatus is configured to connect with a cluster of more than one access point; retain the determined information of the signaling associated with the mobile apparatus; and communicate the information of at least the strength of the signaling towards the cluster of the more than one access point. Further, to determine with signaling received at a mobile apparatus from at least one access point information including a direction and strength of the signaling; retain the determined information of the signaling; use the retained information, identify the access point with the signaling having a strongest beam; and reroute communications with the apparatus towards the access point with the signaling having the strongest beam.

Power control in lte systems operating in unlicensed bands

Abstract: Methods of power control for LTE transmissions in unlicensed bands are described. One method includes determining, at a first device (such as a LTE UE or LTE eNB), a scheduled transmission window for a LTE transmission in an unlicensed band. The transmission window indicates a time for sending the transmission in the unlicensed band. Prior to the scheduled transmission window, the method also includes determining whether a WiFi transmitter is transmitting a signal in the unlicensed band. The method also includes, in response to determining that the transmitter is transmitting in the unlicensed band, determining an adjusted transmission power for the transmission and sending the transmission (such as from an LTE UE to an LTE eNB or from an LTE eNB to an LTE UE) in the transmission window at the adjusted transmission power. Apparatus and computer readable media are also described.

Method, system and apparatus using unique preambles for d2d communications in lte

Abstract: A method is disclosed that includes determining a preamble, at least a portion of which is unique to one or more user equipment for a device-to-device communication of one or more subframes on a band, and performing the device-to-device communication of the one or more subframes comprising the preamble on the band. The band could be, e.g., a lightly-licensed band, a licensed-exempt or unlicensed band, a secondary usage of a band of the licensed band, a band in TV white space, or a licensed band. Apparatus and computer program products are also disclosed.

Band and channel selection in 5g

Abstract: Systems, methods, apparatuses, and computer program products for band and channel selection in a radio system are provided. One method includes generating, by a network entity, at least one performance map showing performance for different portions of spectrum in a wideband radio system. The method may further include combining the at least one performance map with dynamic information, and selecting at least one portion of the spectrum to use for access based on the combined at least one performance map and dynamic information.