D4.3 Final Report on Network-Level Solutions

Research activities in METIS reported in this document focus on proposing solutions to the network-level challenges of future wireless communication networks. Thereby, a large variety of scenarios is considered and a set of technical concepts is proposed to serve the needs envisioned for the 2020 and beyond. This document provides the final findings on several network-level aspects and groups of solutions that are considered essential for designing future 5G solutions. Specifically, it elaborates on: -Interference management and resource allocation schemes -Mobility management and robustness enhancements -Context aware approaches -D2D and V2X mechanisms -Technology components focused on clustering -Dynamic reconfiguration enablers These novel network-level technology concepts are evaluated against requirements defined by METIS for future 5G systems. Moreover, functional enablers which can support the solutions mentioned aboveare proposed. We find that the network level solutions and technology components developed during the course of METIS complement the lower layer technology components and thereby effectively contribute to meeting 5G requirements and targets.Aydin, O.; Valentin, S.; Ren, Z.; Botsov, M.; Lakshmana, TR.; Sui, Y.; Sun, W.... (2015). D4.3 Final Report on Network-Level Solutions. http://hdl.handle.net/10251/7675

Robust message recovery for non-cooperative compute-and-forward relaying

Compute-and-Forward relaying schemes exploit the additive nature of the wireless channel for decoding linear equations/combinations of transmitted messages. However, decoding equations that maximize the computation rate at each relay is in general not optimal from the network perspective. In fact, the (destination) receiver may fail to recover the individual messages even when the relays have successfully decoded linear combinations of them. This paper introduces an easy to implement non-cooperative practical scheme using short linear codes that guarantees a message recovery at the receiver given a successful recovery of linear combinations. We achieve this by putting additional constraints at the relays, which allows us to convert the shortest vector problem into a closest vector problem solvable in polynomial complexity

Harnessing channel collisions for efficient massive access in 5G networks: A step forward to practical implementation

The forthcoming fifth generation of cellular networks (5G) is envisioned to support massive machine type communication (MTC) where a vast number of MTC devices utilize the wireless spectrum to create what is called Internet-of-Things. The vision calls for a paradigm shift in the design and operation of wireless access schemes to enable efficient and reliable massive connectivity with many channel collisions occurring when (uncoordinated) multiple MTC devices concurrently access a shared wireless channel. Motivated by recent results in information theory, this paper proposes a promising approach to the massive access problem by combining the concept of network densification (i.e., ultra-dense deployment of base stations) with physical-layer network coding and pulse-shaped (filtered) OFDM as the most promising air-interface for 5G. The basic idea is to exploit channel collisions at nearby base stations to reliably decode linear equations of transmitted messages. The linear equations are then forwarded through the backbone to a macro base station that solves a system of linear equations to reconstruct the original messages

Towards Massive Connectivity Support for Scalable mMTC Communications in 5G Networks

The fifth generation of cellular communication systems is foreseen to enable a multitude of new applications and use cases with very different requirements. A new 5G multi-service air interface needs to enhance broadband performance as well as provide new levels of reliability, latency, and supported number of users. In this paper, we focus on the massive Machine Type Communications (mMTC) service within a multi-service air interface. Specifically, we present an overview of different physical and medium access techniques to address the problem of a massive number of access attempts in mMTC and discuss the protocol performance of these solutions in a common evaluation framework