Carriers face the challenge to integrate their fixed and mobile infrastructures. In this paper we show results of techno-economic assessment relating to structural convergence and discuss FMC-architectures with respect to functional convergence.

Techno-economic results for 5G back/fronthaul based NG-PON2 with PtP-WDM overlay and WR-WDM-PON for different Radio Access Network (RAN) splits are presented for an urban area. It is shown that the convergence benefit with residential access decreases significantly for high bit rate interfaces.

Techno-economic results for 5G back/fronthaul based NG-PON2 with PtP-WDM-PON overlay and WR-WDM-PON for different RAN splits are presented for an urban area. It is shown that the convergence benefit with residential access decreases significantly for high bit rate interfaces.

Residential access networks of internet service providers have evolved from copper-based public switched telephone networks to digital broadband access networks now based on a mixture of copper and fibre infrastructure components. It is generally well accepted that an FTTH-network (Fibre-to-the-Home), where the fibre runs all the way to the customer

To cope with the forecasted traffic increase in mobile networks small cell deployments are considered as a key enabler. Compared with Macro Sites (MS), Small Cells (SC) will be deployed on a larger scale and thus require a more cost effective transport connection than in today's CWDM backhaul networks. An important question for this transport network is "Is it preferable to have a common converged transport network in the access aggregation to cope with fixed mass market and potentially new small cell sites or is a separate network for the SC better?".This paper investigates NG-PON2, and WDM-PON with different flavours as well as CWDM as a reference for different backhaul and fronthaul architectures. The results show the cost for the different transport options as a function of number of deployed small cells considering both FTTC and FTTH areas. From these results one can conclude that re-using an already deployed mass market solution is not always the most beneficial choice.

Mobile traffic is heavily increasing in the last years and a massive continuous growth is forecasted for the next decade. To cope with this significant traffic increase in mobile networks and the further evolving competitive market situation, operators are looking for solutions to increase the capacity of their mobile networks, while keeping the cost low. Besides enhancements of mobile radio technology and adding new spectrum to the existing sites, densification of radio sites, by so called small cells, is considered as a very promising option to increase capacity. Adding small cells to the already existing macro cell layer lead to heterogeneous networks (HetNet). Because of the scarce radio spectrum it is most likely that the radio sites in HetNets will use the same frequencies and therefore create interferences. To mitigate this impact different coordination methods have been proposed creating new challenging requirements on the transport network compared to today's backhaul. Cost effective and scalable transport solutions are an important fundament for wide and successful deployment of HetNets. This paper investigates and assesses techno-economically different architectures for backhaul and fronthaul transport of existing and newly deployed radio sites in HetNet architectures taking requirements from interference co-ordination into account.

Increasing bandwidth demand drives the need for next-generation optical access (NGOA) networks that can meet future end-user service requirements. This paper gives an overview of NGOA solutions, the enabling optical access network technologies, architecture principles, and related economics and business models. NGOA requirements (including peak and sustainable data rate, reach, cost, node consolidation, and open access) are proposed, and the different solutions are compared against such requirements in different scenarios (in terms of population density and system migration). Unsurprisingly, it is found that different solutions are best suited for different scenarios. The conclusions drawn from such findings allow us to formulate recommendations in terms of technology, strategy, and policy. The paper is based on the main results of the European FP7 OASE Integrated Project that ran between January 1, 2010 and February 28, 2013.

This study analyses and compares various small cell backhaul deployment scenarios considering different starting situations, backhaul technologies, and small cell locations.

The orthogonal frequency division multiple access (OFDMA)-based passive optical network (PON) is a potential candidate to meet the flexibility requirements for next-generation optical access networks. We propose an OFDMA-based PON with a transmission employing intensity modulation/direct detection in the downstream and a remodulation of a remotely seeded carrier provided by the optical line terminal with coherent detection in the upstream, which enables cost-effective colorless optical network units (ONUs). Furthermore, an OFDMA-PON field trial using the proposed scheme over 37.5 km feeder fiber is demonstrated. A power budget supporting 32 ONUs with dynamic bandwidth allocation and trellis coded modulation (TCM) is reported.

Transmission capabilities of a coherent real-time UDWDM PON over deployed fibers in two testbeds (Berlin and Darmstadt, Germany) are demonstrated. Extensive coexistence tests including LTE backhauling and GPON, RF-Video, 100G and OTDR were performed. A silicon photonics-integrated CMOS laser was used for parts of the trial.

OFDM is an interesting candidate to meet the requirements of high flexibility and speed for the next generation optical access networks. We show an OFDM system utilizing a timing advance tracking algorithm to realize a synchronized upstream transmission. Therefore, a dynamic bandwidth allocation can be used in the upstream and an interleaved assignment is made possible. We then demonstrate the feasibility in a field trial with four individual ONUs using a 37.5 km field deployed feeder fiber of the Deutsche Telekom AG. Power loading and the trellis coded modulation was used to achieve a power budget supporting 32 ONUs for up- as well as downstream transmission.

An OFDMA-PON field trial using coherent detection in upstream and direct detection in downstream on 37.5 km feeder fiber is demonstrated. A power budget supporting 32 cost-effective colorless ONUs with dynamic bandwidth allocation is reported.

An open converged metro-access network approach allows for sharing optical layer resources like fibers and optical spectrum among different services and operators. We demonstrated experimentally the feasibility of such a concept by the simultaneous operation of multiple services showing different modulation formats and multiplexing techniques. Flexible access nodes are implemented including semiconductor optical amplifiers to create a transparent and reconfigurable optical ring network. The impact of cascaded optical amplifiers on the signal quality is studied along the ring. In addition, the influence of high power rival signals in the same waveband and in the same fiber is analyzed.

To achieve a joint optimization of fixed and mobile networks, we propose a new broadband network architecture organized around the innovative concept of Next Generation Point of Presence (NG-POP). NG-POP targets a disruptive evolution of the first aggregation node, also called Central Office (CO), or Local POP by opposition to more centralized POPs. It will allow both a better distribution of all essential functions of fixed and mobile networks (functional convergence) and a better mutualisation of fixed and mobile equipment and infrastructures (structural convergence). This paper presents the main ideas related to functional and structural convergence and illustrates the benefits expected from the underlying NG-POP concept for future converged fixed and mobile networks. The architectural concepts presented in this paper will be assessed in details in European large scale integrating project COMBO (COnvergence of fixed and Mobile BrOadband access/aggregation networks).

Passive optical network (PON) monitoring with as many as 1024 subscribers encounters difficulties due to high splitting losses and drop fiber differentiation problems. In this work a novel concept for monitoring PONs for fiber to the home (FTTH) access, which is based on concatenated wavelength-selective mirrors, has been investigated in a field trial. At each subscriber a unique mirror combination is installed. Binomial coefficients guarantee that each mirror combination in a given PON is used only once. The field trial has been performed successfully with a PON consisting of 37 km deployed standard single-mode fiber and up to 1:32 passive optical power splitting causing a total one-way attenuation of at least 30.7 dB. Different subscribers located at equal distances from the optical time domain reflectometry could be distinguished and identified individually. For the measurement setup only low-cost components were used.

Field trial results of high resolution optical frequency modulated continuous wave (FMCW) monitoring approaches are presented. The variable chirp rate technique and the phase noise cancellation method show promising results on a deployed fiber PON-infrastructure.

Our novel PON monitoring concept succeeded in a field trial. Subscribers located at equal distances were individually identified across a PON with at least 30.7 dB one-way loss and utilization of low cost components.

A new concept for unified access and aggregation network architecture allowing fixed and mobile networks to converge is proposed based on the concepts of Next Generation POP combining structural and functional convergence.

The ACCORDANCE OFDMA-PON architecture has been proposed as an attractive candidate for next generation PON networks. The benefits brought by this concept include ultra-high data rates, extensive node consolidation and convergence of multiple services within the same optical distribution network infrastructure, more flexible, two-dimensional bandwidth management, as well as the opportunity for cross-layer optimization. Moreover, OFDMA-PON is expected to scale better to increased (> 10 Gbps) aggregate data rates than existing TDMA-PONs. The ACCORDANCE project addresses a wide range of aspects related to OFDMA-PON. This includes architectural issues, physical layer OFDM transmission studies, OLT/ONU Tx/Rx system design, MAC protocol and algorithm design/implementation and wireless backhauling/fronthauling. This paper provides an overview of the activities within the ACCORDANCE consortium and the solutions selected by the project partners to address the aforementioned issues.

A method to distinguish single- and equidistant multi-target reflections in optical monitoring is successfully demonstrated. The polarization dependent transmission in field deployed fiber PON-infrastructure was evaluated by combining polarization diversity detection with frequency modulated continuous-wave.