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This paper aims to propose one possible approach in the setting of VHCNs (Very High Capacity Networks) performance targets that should be capable of promoting efficient investments for operators and, at the same time, improving the benefits for end-users. To this aim, we suggest relying on some specific KPIs (Key Performance Indicators), especially throughput - i.e., the bandwidth as perceived by the customer - valid at the application layer, instead of the physical layer data-rate. In this regard, the paper underlines that the bandwidth perceived is strictly linked to the latency. The most important implication is that some of the most demanding services envisaged for the future (e.g., mobile virtual and augmented reality, tactile internet) cannot be met by merely increasing the low-level protocol data-rate. Therefore, for the VHCNs reducing latency through Edge Cloud Computing (ECC) is a mandatory pre-requisite., Comment: 6 pages, 4 figures, 1 table

For very high capacity networks (VHC), the main objective is to improve the quality of the end-user experience. This implies compliance with key performance indicators (KPIs) required by applications. Key performance indicators at the application level are throughput, download time, round trip time, and video delay. They depend on the end-to-end connection between the server and the end-user device. For VHC networks, Telco operators must provide the required application quality. Moreover, they must meet the objectives of economic sustainability. Today, Telco operators rarely achieve the above objectives, mainly due to the push to increase the bit-rate of access networks without considering the end-to-end KPIs of the applications. The main contribution of this paper concerns the definition of a deployment framework to address performance and cost issues for VHC networks. We show three actions on which it is necessary to focus. First, limiting bit-rate through video compression. Second, contain the rate of packet loss through artificial intelligence algorithms for line stabilization. Third, reduce latency (i.e., round-trip time) with edge-cloud computing. The concerted and gradual application of these measures can allow a Telco to get out of the ultra-broadband "trap" of the access network, as defined in the paper. We propose to work on end-to-end optimization of the bandwidth utilization ratio. This leads to a better performance experienced by the end-user. It also allows a Telco operator to create new business models and obtain new revenue streams at a sustainable cost. To give a clear example, we describe how to realize mobile virtual and augmented reality, which is one of the most challenging future services., Comment: 42 pages, 4 tables, 6 figures. v2: Revised English

Self- and alien-FEXT disturbances on the same cable severely limit performance in the commonly employed VDSL2 17a, i.e. 17.6 MHz, standard profile. Then, in a multi-operator environment, VDSL2 may be unable to provide the 100 Mbit/s speed required by the EC's policy target, unless vectoring is adopted along with a suitable Multi-Operator Vectoring (MOV) technique. Some vendors recently proposed enlarging the bandwidth up to 35.2~MHz (so-called e-VDSL) as one possible solution to increase the 100 Mbit/s coverage. However, as we show in the paper, the bandwidth advantage is illusory as an "ideal MOV" is not implementable with today's technology, and alien-FEXT practically destroys the envisaged data-rate increase. Therefore, we introduce the Sub-band Vectoring (SBV) technique, as one practical solution, which turns out to be near optimal in terms of achievable data-rate, as well as incremental for those Countries where the NRA adopts sub-loop unbundling regulation. SBV adopts a novel frequency division multiplexing approach, which imposes one fairness condition to equalize data-rate values and overall bandwidth per operator at different distances. The paper shows that e-VDSL with SBV is robust, as it can cope with relatively high values of vectoring impairments. It also shows that the SBV allows up to three co-located operators with e-VDSL to coexist, without imposing any of the burdensome coordination limitations of the ideal MOV architecture. Our results show that the SBV allows achieving up to 210 Mbit/s per user for e-VDSL and up to 620 Mbit/s per user for a bandwidth expanded up to 105.6 MHz, with two telecom operators. Finally, the paper shows that a migration strategy towards usage of the G.fast standard thanks to SBV is achieved in a simple way., Comment: 11 pages, 8 figures and 2 tables

The most effective way to promote Next Generation Access coverage and ultra-broadband penetration is through infrastructure competition., Comment: 22 pages, 10 figures and 2 tables

In this paper the analysis of mobile satellite systems adopting constellations of multi-spot satellites over non-geostationary orbits is addressed. A link design procedure is outlined, taking into account system spectrum efficiency, probability of bit error and outage probability. A semi-analytic approach to the evaluation of outage probability in the presence of fading and imperfect power control is described, and applied to single channel per carrier (SCPC) and code division multiple access (CDMA) techniques. Some results are shown for the Globalstar, Iridium and Odyssey orbital configurations.