In this paper, we provide an overview on backhaul requirements in mobile networks featuring inter-site cooperation. We consider a heterogeneous deployment, where small cells are embedded into macro-cells. For reducing inter-cell interference, we consider intra- and inter-site joint transmission (JT)-coordinated multi-point (CoMP) in fully flexible cooperation clusters. Backhaul traffic for a macro-cell site scales linearly with the number of small cells and multiplicative by introducing cooperation. All features in LTE-Advanced together push the backhaul traffic up to 100 Gbit/s per site. JT-CoMP is sensitive to the feedback delay.We consider an exemplary rural fiber to the home (FTTH) network as mobile backhaul and find that delays between adjacent sites are below 1 ms. Impairment effects due to the delay can be reduced by feedback compression, shorter delays in the air interface and Doppler-delay based channel prediction.

Backhaul requirements for inter-site cooperation in heterogeneous LTE-Advanced networks

New software-defined open network concepts are proposed in this paper to enable an efficient implementation of front- and backhaul solutions for future 5G mobile networks. Main requirements for 5G front- and backhaul are derived and then related to the open network architecture enabling multiple operators to share the same physical infrastructure. The value of software-defined networking (SDN) is particularly outlined therefore. For the use of SDN in the fronthaul, CPRI over Ethernet (CoE) is proposed as a new transport protocol. In the backhaul, distributed security can be implemented using SDN where direct links are confined inside the access domain, as opposed to the current centralized security solution including also the transport domain. In this way, low latency can be realized e.g. for machine-type communications. As the benefits for fixed-mobile convergence are evident, SDN should be enabled increasingly in the access domain.

/pdf/software-defined-open-architecture-for-front-and-backhaul-in-130esigdav.pdf

Software-defined open architecture for front- and backhaul in 5G mobile networks

In this paper, two different models for permanent user channel assignment, based on Markov chain, are proposed for wireless cellular networks. Both models include channels for calling, handover, and permanent assignment. Models in this paper provide comparison of the blocking probabilities and handover failure probabilities after introducing the permanent user channel assignment, further permanent user channel blocking probability is also derived. Based on the blocking probability results, risk analysis to predict the blocked channels is provided at the end of this paper using the @Risk tool. The simulation results are provided in two parts, i.e. (1) the probability curves against the number of assigned channels are shown and (2) the results using @Risk tool for the risk analysis are shown.

Channel Allocation Schemes for Permanent user Channel Assignment in Wireless Cellular Networks

With the expected surge in the global IP traffic, service providers would need to adapt accordingly to operate disruption and loss free networks supported with the developing IP infrastructure. With the disposal of the hierarchical network structure, radio access networks are moving towards a flat-IP architecture and novel topological set-ups in the backhaul. Hence, a routing paradigm that employs suitable Traffic Engineering (TE) techniques aligned with the developing nature of future access networks must be applied. It becomes imminent that the routing considerations for IP access networks converge with the ones found in conventional intra-domain routing. In this paper, Multi-Plane Routing (MPR) that consolidates various aspects in all-IP infrastructure is extensively studied in access network structures. We propose a MPR-based TE approach considering two different scenarios to reflect the evolution in the architectural design of access network structures under a realistic traffic scenario with a varying range of internal/external traffic. Moreover, a new optimization framework for the offline and online TE mechanisms of MPR have been formulated. Accordingly, a practical performance evaluation testing the validity of the aforementioned scenarios is presented. Our simulation results demonstrate extensive analysis in terms of several performance criteria in networks. It is convincingly shown that for ranges of topologies, MPR's utilization of whole topology in building path diversity in networks, allows for significant improvement of networks capacity, performance, and support for meshing.

/pdf/analysis-of-practical-aspects-of-multi-plane-routing-based-4fi4vjwywx.pdf

Analysis of Practical Aspects of Multi-Plane Routing-Based Load Balancing Approach for Future Link-State Convergent All-IP Access Networks

A radio communication system includes a first base station that includes a control part that sets an interface between the first base station and a second base station, the second base station having information to be used for adjusting between a protocol that is set between a host station and the first base station and a protocol that is set between the first base station and a relay station, and a communication module that carries out communication between the first base station and the host station through the interface that is set by the control part; and the relay station that carries out radio communication with the first base station and includes a control part that sets a protocol between the relay station and the second base station through an interface that is set between the relay station and the second base station.

Radio communication system, base station and relay station

Long term evolution technologies provide new standards in mobile communications regarding available bandwidth. It is expected that users of one radio cell will share more than 100 Mbit/s in future. To take advantage of the full feature set of next generation mobile networks, transport network design has to face new requirements, caused by the architectural changes of LTE technologies. Especially the newly defined X2 interface impacts on the transport network requirements. X2 enables direct communication between evolved base stations (eNBs) and thus, enforces local solutions. At the same time a tendency of locating network elements at fewer, central sites to reduce operational expenditure can be observed, in particular concerning the transport layer. This leads to the question of how the direct X2 connection of eNBs on the logical layer can be accommodated with a general centralization of transport networks. Our considerations show that for LTE, a centralized transport network is able to realize the local meshing between eNBs. However, for LTE Advanced, the standards currently discussed by the 3GPP initiative could lead to enhanced requirements on the X2 interface latency. Consequently, the implications for the network architecture have to be analyzed in more detail. Keywords—backhauling, LTE Advanced, mobile network de-

/pdf/requirements-of-4g-based-mobile-broadband-on-future-1aid3ea5cx.pdf

R. Nitsch

Papers

Requirements of 4G-Based Mobile Broadband on Future Transport Networks