We demonstrate the performance of a nonlinear compensation scheme based on the Volterra Series on a 224 Gb/s PolMux-16QAM system over 250 km of fibre and comment on its improvement in performance over linear equalization.

This paper presents a work in progress done within an Interreg Europe project called ERUDITE. The aim of the project is to create a process that enables regional stakeholders across Europe to co-identify and co-design appropriate and innovative digital services on the top of high speed broadband, based on existing needs and a recognition of the social, economic and environmental value that they have the potential to generate to society as a whole.

FTTH networks based on Open Access have been very common in Finland and especially Sweden in the past 10 - 15 years. In such networks, an operator-neutral network provider (NP) offers competing service providers access to the end users under non-discriminatory conditions. Among the advertised benefits of open FTTH networks is the development of an open market for high-quality digital societal services, such as e-health and e-social care. During the past six months, the EU Connected for Health project has run three pilots in Finland and Sweden, in which digital home-care services have been tested in live networks by municipalities and home-care givers. The pilots allowed to assess the socio-economic impact of fibre-based digital home-care services, in terms of costs, savings, and quality-of-life impact. During this talk we will present the final results of the study.

We propose a cost-effective way to increase the non-linear tolerance of all channels in a 40-Gb/s WDM transmission system, which is shown to greatly improve the performance of RZ and especially NRZ transmission.

We present the first numerical study of 67%-duty-cycle single-MZM APRZ, comparing it with 33% RZ, 33% APRZ and standard CSRZ. This transmitter is shown to combine CSRZ implementation simplicity with the improved nonlinear tolerance of π/2-APRZ.

The Asynchronous Phase Modulation (APM) scheme is experimentally studied for the first time. APM is shown to increase the power tolerance of NRZ-OOK over a 3x75-km link. © 2006 Optical Society of America.

We use the cost-effective APM technique to increase the non-linear tolerance of NRZ-OOK, and we demonstrate, in a recirculating loop experiment, the transmission over 2800 km SSMF of 16 NRZ-OOK 40 Gb/s channels with 100 GHz spacing.

We use the cost-e®ective APM technique to increase the non-linear tolerance of NRZ-OOK, and we demonstrate, in a recirculating loop experiment, the transmission over 2800 km SSMF of 16 NRZ-OOK 40 Gb/s channels with 100 GHz spacing. © 2007 Optical Society of America.

We demonstrate experimentally as well as numerically that the alternate-phase return-to-zero modulation format increases the nonlinear tolerance of strongly dispersion-managed 40-Gb/s transmission. An analysis of phase misalignment is also presented.

In this paper, an efficient single Mach-Zender modulator (MZM) implementation of alternate-phase return to zero (APRZ), which combines carrier-suppressed return to zero (CSRZ)'s ease of implementation with APRZ's nonlinear tolerance, is analyzed. In particular, the first numerical study of 67%-duty-cycle single-MZM APRZ over a 40-Gb/s 5 × 100-km link, in terms of nonlinear, dispersion, and filtering tolerance, comparing it with 33% RZ, 33% APRZ, and standard 67% CSRZ, is presented. The results show that APRZ with phase shift close to π/2 is the optimum choice, independent of specific transmitter implementation. A new mechanism is also discovered, based on the interference of ghost pulses with the original pulse train, which improves the nonlinear tolerance of CSRZ in a 40-Gb/s transmission

Intrachannel four-wave mixing (IFWM) represents main source of impairments in fiber transmission at 40 Gb/s. A number of phase modulation techniques have been proposed to suppress the IFWM. In this paper, we study a cost-effective way of increasing the nonlinear tolerance of a 40-Gb/s wavelength division multiplexing transmission system by asynchronous phase modulation (APM). This can be achieved with one phase modulator placed after the wavelength multiplexer so that cost is shared by all channels. We show, by means of numerical simulations and laboratory experiments, that APM greatly improves the performance of ON-OFF-keying transmission.

We report the first field transmission experiment using the APRZ modulation format for 40-Gb/s transmission through 540 km SSMF, which confirms the improved nonlinear tolerance of APRZ. The optimum phase-modulation amplitude in this experiment is p/2. 

We use the cost-effective APM technique to increase the non-linear tolerance of NRZOOK, and we demonstrate, in a recirculating loop experiment, the transmission over 2800 km SSMF of 16 NRZ-OOK 40 Gb/s channels with 100 GHz spacing.

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. 

There is a wide range of FTTH initiatives throughout Sweden, with investments made by both telecom operators and public actors. The benefits of the investments are often discussed, especially when the investment is made by municipalities or other public bodies. This preliminary study analyses the socio-economic impacts of the investment in FTTH. The goal of the study was: Is it possible to calculate how much a krona (SEK) invested in fibre will give back to society? The conclusion is that a more comprehensive statistical data and more calculations are needed to give an exact estimate. The study, however, provides an indication that 1 SEK invested over four years brings back a minimum of 1.5 SEK in five years time. The study estimates the need for investment to achieve 100% fibre penetration, identifies and quantifies a number of significant effects of fibre deployment, and then calculates the return on investment. We recommend a more extensive study, in which the proposed model is refined and expanded with more detailed and updated data. This pre-study was sponsored by the Swedish Government’s Broadband Council (Bredbandsforum).

We analyse the extent of the annual net cost reductions stemming from the introduction of four FTTH- enabled digital services for home care, as recently introduced in the Swedish city of Västerås. In total, between 2014 and 2020, it is projected that Sweden could save up to between €3 and €6 billion if such services were massively deployed today. The cost reductions are analysed for three different types of municipality. The article also shows that there is a significant cost reductions potential for a less extensive (and more realistic) deployment scenario with only 10% of users using digital services.

In this paper we present some recent work we performed on the socio-economic impact of fibre access networks (FTTH/FTTx). We summarise some results from a pre-study on the effects of fibre deployments in Sweden. Specifically, we list and quantify savings in data and telecommunications costs for Swedish local governments, estimate the added values for fibre-connected citizens, and present a multivariate regression analysis of the early impact on employment and population evolution, building on data from 290 municipalities between 2007 and 2010: we find a weak but statistically significant correlation, and we are able to exclude backward causality.

We analyse Stockholm City's fibre access network investment model and its effects on the different stakeholders, and for society at large. Moreover, Stockholm is compared to Copenhagen, which has conditions similar to Stockholm, but where the municipality has not taken an active role in the city's fibre network. The socio-economic return on the fibre infrastructure investment is estimated to over 16 billion SEK, or €1.85 billion at the current exchange rate (nearly three times the investment). This result is based on a few quantifiable effects alone and we expect the actual return to be considerably larger.

—The authors propose a modulation format in which the phase of the signal pulses alternates, in order to reduce the intrachannel four-wave mixing. They demonstrate numerically that the performance of a 40-Gb/s transmission link can be substantially improved.

The nonlinear effects of amplitude jitter and ghost pulse generation, which are present in strongly dispersion-managed optical communication systems can be suppressed by alternation of the phase of the bits. A physical explanation for this effect is given that shows that with suitably chosen phase modulations the processes that give rise to the nonlinear effects will counteract each other.

The social-economic impact of broadband has been studied extensively. The consensus is that basic broadband (from none or upgraded from 256 kbps to the order of 2 - 6 Mbps) indeed has positive impact on economic growth and performance in terms of e.g. GDP and employment. Nevertheless, studies on the social-economic impact of high-speed broadband access (20-30 Mbps and beyond) are far more controversial showing a mixed picture. In this paper, we investigated fiber broadband access impact on the employment rate, population evolution, reduced driving distance per capita and new company registrations at the municipality level in Sweden using multiple regression analysis. Based on the availability of historical fiber network deployment data, analyses can be carried out by regressing current values of social-economic indicators under study on the fiber penetration levels 4 years earlier, hence reverse causality in the regression analyses can be tackled effectively. Our results show that, given all the other significant factors remain the same and with at least 90% confidence interval, 10% increase of fiber broadband penetration would result in 0.17% population increase, 0.32% employment rate enhancement, 28.7 km reduced driving distance per capita per year, and one new company among 17857 inhabitants.

Several schemes for suppressing infra-channel non-linearities by introducing phase shifts between pulses are compared. Simulations and experiments show that sinusoidal phase modulation at 10 GHz provides a simple and effective means for improving the nonlinear tolerance in 40 Gbit/s transmission.

A proposed improvement of the nonlinear tolerance in 40 Gbit/s optical transmission by applying a 10 GHz phase modulation is presented. The improvement is obtained because intra-channel four-wave mixing (IFWM) is suppressed. It is shown, both by numerical simulations and experiments, that the penalty induced by IFWM is significantly reduced.

We propose to suppress intra-channel four-wave-mixing (IFWM) in 40 Gbit/s optical transmission by applying a phase modulation at 10 GHz. Both numerical simulations and experiments show that the penalty induced by IFWM is significantly reduced

Följande rapport är skriven av RISE Research Institutes of Sweden, på uppdrag av Svenska Stadsnätsföreningen, med syftet att ge insyn i och förståelse för vilka möjligheter ett uppkopplat samhälle kan skapa samt å andra sidan hur ett samhälle kan påverkas om aktörer såsom offentlig sektor, enskilda individer och företag saknar en fullgod uppkoppling. Ett mål med rapporten är att öka förståelsen för vilka tekniska förutsättningar som krävs för att delta fullt ut det digitala samhället. Rapporten presenterar ett antal troliga framtidsscenarier kopplat till “framtidens smarta och uppkopplade samhälle” – där fiber ingår som en del av infrastrukturen – och tillhörande “motsatsscenarier” (beskrivna som “spegelscenarier”) – där fiber inte finns tillgängligt. Dessa scenarier utspelar sig år 2030 i en fiktiv by kallad Ytterbyn.

We report on the versatility of frequency resolved optical gating using an electro-absorption modulator to accurately characterise the pulse shape and phase of high speed telecommunication pulses, as well as properties of optical components.

We demonstrate the use of spectrograms for pulse monitoring. The technique can characterize the phase and intensity of data modulated pulses after transmission over a fiber span including a tunable dispersion compensating grating. © 2006 Optical Society of America.

With ever increasing demands on spectral efficiency, complex modulation schemes are being introduced in fiber communication. However, these schemes are challenging to implement as they drastically increase the computational burden at the fiber receiver's end. We perform a feasibility study of implementing a 16-QAM112-Gbit/s decision directed equalizer on a state-of-the-art FPGA platform. An FPGA offers the reconfigurability needed to allow for modulation scheme updates, however, its clock rate is limited. For this purpose, we introduce a new phase correction technique to significantly relax the delay requirement on the critical phase-recovery feedback loop.