People

Professor Stuart Walker

Professor
School of Computer Science and Electronic Engineering (CSEE)
Professor Stuart Walker
  • Email

  • Telephone

    +44 (0) 1206 872413

  • Location

    1NW.3.16, Colchester Campus

  • Academic support hours

    By appointment

Profile

Biography

Prof. Stuart Walker obtained his degree in Physics from Manchester University in 1973 and subsequently was awarded an M.Sc. in Telecommunications Systems and a Ph.D. in Electronics in 1975 and 1981 respectively; both from the University of Essex. In 1982 he joined British Telecom Research Laboratories in their submarine optical transmission systems division. At BT he pioneered the concept of unrepeatered transmission systems and in 1987 was promoted to head the transatlantic link repeater group. In 1988, he became Senior Lecturer at Essex University where his research interests widened to also include access network technologies. He was promoted to Full Professor in 2004. Recent involvement with the EPSRC included the platform grants EP/E04610X/1: Future Photonic Networks and GR/S82695/01: Next Generation Photonic Networks. He has maintained extensive involvement in EU projects projects such as MUSE-1, MUSE-2, UROOF, OASE, STRONGEST, FIVER, and SODALES. He has also been active in the Networks of Excellence, e-Photon/One, e-Photon/One+ and BONE. He leads the Access Group at Essex University which conducts research on wireless and wireline media for the last mile. Member of the Future Networks Research Group Access Networks Lab web pages (See also:staff research interests by category)

Qualifications

  • BSc

  • MSc

  • PhD

Research and professional activities

Research interests

High-capacity optical network systems

semiconductor laser characteristics

broadband optical receiver design

optical transmission

local access architectures based on arrayed waveguide gratings

video compression

Current research

active remote nodes for access networks

Conferences and presentations

4. Femi-Jemilohun, Oladunni J and S.D.Walker Investigation of beam-forming effectiveness in 802.11ac indoor wireless links. Network Communications 2013. June 1st 2013 Istanbul.

5.Femi-Jemilohun, Oladunni J and S.D.Walker: OPTIMIZATION OF BEAMFORMING TECHNOLOGY FOR COGNITIVE SPATIAL ACCESS IN MILLIMETRE WAVE Applications ICTRS 2013 July 2013 Netherlands 6. S.D.Walker et al. On-the-Field Demonstration of Quintuple-Play Service Provision in Long-Reach OFDM-based WDM-PON Access Networks ECOC2013, September 2013 London.

1.Terence Quinlan, Nick Warren, Stuart Walker,A 1.5 GHz Bandwidth, Linear Polarisation Switchable, 5 GHz Crossed Rectangular Patch Antenna, Loughborough Antennas & Propagation Conference, Loughborough, November 2012.

2. Fariborz Mahmouli and S.D.Walker, Orbital Angular Momentum Generation in a 60- GHz Wireless Radio Channel, TELFOR 2012, Belgrade, November 2012 3. Anthony O. Adeyemi-Ejeye and Stuart D. Walker Ultra-High Definition Wireless Video Transmission using H.264 over 802.11n WLAN Challenges and Performance Evaluation. Zagreb CONTEL 2013 June 28-30,2013.

Teaching and supervision

  • Analogue Circuit Design (CE263)

  • Telecommunication Principles (CE265)

  • Networking Principles (CE703)

  • Directed Studies (CE891)

Publications

Journal articles (118)

Parker, MC. and Walker, SD., Information Transfer Time: The Role of Holomorphism, Stationary Phase, and Noise

Parker, MC., Rochat, E. and Walker, SD., Fourier Transform Model for All-Order PMD Compensation based on a Coupled-Mode Equation Solution using the First Born Approximation

Niknia, E., Toycan, M. and Walker, SD., (2018). Energy efficient operation for a reconfigurable and self-interleaved optical access network. Computers and Electrical Engineering. 66, 189-199

Habib, U., Aighobahi, AE., Quinlan, T., Walker, SD. and Gomes, NJ., (2018). Analog Radio-over-Fiber Supported Increased RAU Spacing for 60GHz Distributed MIMO employing Spatial Diversity and Multiplexing. Journal of Lightwave Technology

Kaka, AO., Toycan, M. and Walker, SD., (2018). Circularly polarized implantable antenna characterization for retinal prosthesis systems. Turkish Journal of Electrical Engineering and Computer Sciences. 26 (3), 1180-1189

Neokosmidis, I., Rokkas, T., Parker, MC., Koczian, G., Walker, SD., Siddiqui, MS. and Escalona, E., (2017). Assessment of socio-techno-economic factors affecting the market adoption and evolution of 5G networks: Evidence from the 5G-PPP CHARISMA project. Telematics and Informatics. 34 (5), 572-589

Adeyemi-Ejeye, A., Alreshoodi, M. and Walker, SD., (2017). Implementation of 4kUHD HEVC-content transmission. Multimedia Tools and Applications. 76 (17), 18099-18118

Siddiqui, M., Legarrea, A., Escalona, E., Parker, M., Koczian, G., Walker, S., Lyberopoulos, G., Theodoropoulou, E., Filis, K., Foglar, A., Ulbricht, M., Liu, Y., Point, J., Trouva, E., Rokkas, T., Neokosmidis, I., Kritharidis, D., Katsaros, K., Spirou, S., Habel, K., Jungnickel, V., Canales, C. and Lorenzo, M., (2016). Hierarchical, virtualised and distributed intelligence 5G architecture for low-latency and secure applications. Transactions on Emerging Telecommunications Technologies. 27 (9), 1233-1241

Boucouvalas, AC., Wilner, A., Zervas, M., Walker, S. and Schachterr, L., (2016). Introduction to the Issue on Optical Waveguide Technology and Applications. IEEE Journal of Selected Topics in Quantum Electronics. 22 (2), 5-7

M. Alreshoodi, A. O. Adeyemi-Ejeye, J. Woods and S. D. Walker, (2015). Fuzzy logic inference system-based hybrid quality prediction model for wireless 4kUHD H.265-coded video streaming. IET Networks. 4 (6), 296-303

Kaka, AO., Toycan, M. and Walker, SD., (2015). Miniaturized stacked implant antenna design at ISM band with biocompatible characteristics. COMPEL - The international journal for computation and mathematics in electrical and electronic engineering. 34 (4), 1270-1285

Bade, MG., Toycan, M. and Walker, SD., (2015). Cost and energy efficient operation of converged, reconfigurable optical wireless networks. Optical Switching and Networking. 18 (P1), 71-80

Musa, IK., Walker, SD., Owen, AM. and Harrison, AP., (2014). Self-service infrastructure container for data intensive application. Journal of Cloud Computing: Advances, Systems and Applications. 3 (1), 5-5

Quinlan, T. and Walker, SD., (2014). A Polarization Switched, Narrowband, RF Probe System Using a VCSEL Optical Feed. IEEE Sensors Journal. 14 (12), 4348-4353

Parker, MC. and Walker, SD., (2014). A Unified Carnot Thermodynamic and Shannon Channel Capacity Information-Theoretic Energy Efficiency Analysis. IEEE Transactions on Communications. 62 (10), 3552-3559

Femi-Jemilohun, OJ., Quinlan, T., Barc, S. and Walker, SD., (2014). An Experimental Investigation Into GbE Wireless Data Communication at 24 GHz in Non-Line-of-Sight and Multipath Rich Environments. IEEE Antennas and Wireless Propagation Letters. 13, 1219-1222

Adeyemi-Ejeye, AO. and Walker, S., (2014). 4kUHD H264 Wireless Live Video Streaming Using CUDA. Journal of Electrical and Computer Engineering. 2014, 1-12

Quinlan, T. and Walker, S., (2014). A Coaxial, 60-GHz, 15.3-dBi Slot Antenna Array. IEEE Antennas and Wireless Propagation Letters. 13, 818-821

Llorente, R., Morant, M., Pellicer, E., Herman, M., Nagy, Z., Alves, T., Cartaxo, A., Herrera, J., Correcher, J., Quinlan, T., Walker, S., Rodrigues, C., Cluzeaud, P., Schmidt, A., Piesiewicz, R. and Sambaraju, R., (2014). On-the-field performance of quintuple-play long-reach OFDM-based WDM-PON optical access networks. Optics Express. 22 (6), 6203-6203

Alshahrani, AM. and Walker, S., (2014). Implement A Novel Symmetric Block Cipher Algorithm. International Journal on Cryptography and Information Security. 4 (4), 1-11

Femi-Jemilohun, OJ. and Walker, S., (2014). Performance Evaluation of 24GHz Spectrum Indoor Wireless Radio Links. International Journal of Emerging Technology and Advanced Engineering. 4 (11)

Musa, IK., Walker, S., Owen, AM. and Harrison, AP., (2014). Self-service infrastructure container for data intensive application. Journal of Cloud Computing: Advances, Systems and Applications. 3 (1), creators-Walker=3AStuart=3A=3A

Mahmouli, FE. and Walker, SD., (2013). 4-Gbps Uncompressed Video Transmission over a 60-GHz Orbital Angular Momentum Wireless Channel. IEEE Wireless Communications Letters. 2 (2), 223-226

Kaka, AO., Toycan, M., Bashiry, V. and Walker, SD., (2012). Modified Hilbert fractal geometry, multi‐service, miniaturized patch antenna for UWB wireless communication. COMPEL - The international journal for computation and mathematics in electrical and electronic engineering. 31 (6), 1835-1849

Hugues-Salas, E., Giddings, RP., Jin, XQ., Hong, Y., Quinlan, T., Walker, S. and Tang, JM., (2012). REAM intensity modulator-enabled 10Gb/s colorless upstream transmission of real-time optical OFDM signals in a single-fiber-based bidirectional PON architecture. Optics Express. 20 (19), 21089-21089

Quinlan, T., Dudley, S., Morant, M., Llorente, R. and Walker, S., (2012). VCSEL-based, CWDM - PON systems using reflective technology for bi-directional multi-play service provision. Optics Express. 20 (15), 16726-16726

Hugues-Salas, E., Giddings, RP., Jin, XQ., Hong, Y., Quinlan, T., Walker, S. and Tang, JM., (2012). REAM intensity modulator-enabled 10Gb/s colorless upstream transmission of real-time optical OFDM signals in a single-fiber-based bidirectional PON architecture. Optics Express. 20 (19), creators-Walker=3AStuart=3A=3A

Parker, MC. and Walker, SD., (2011). Roadmapping ICT: An Absolute Energy Efficiency Metric. Journal of Optical Communications and Networking. 3 (8), A49-A49

Wallace, D., Eltiti, S., Ridgewell, A., Garner, K., Russo, R., Sepulveda, F., Walker, S., Quinlan, T., Dudley, S., Maung, S. and others, (2011). Cognitive and physiological responses in humans exposed to a TETRA base station signal in relation to perceived electromagnetic hypersensitivity. Bioelectromagnetics. 33 (1), 23-39

Jin, XQ., Wei, JL., Giddings, RP., Quinlan, T., Walker, S. and Tang, JM., (2011). Experimental Demonstrations and Extensive Comparisons of End-to-End Real-Time Optical OFDM Transceivers With Adaptive Bit and/or Power Loading. IEEE Photonics Journal. 3 (3), 500-511

Morant, M., Llorente, R., Hauden, J., Quinlan, T., Mottet, A. and Walker, S., (2011). Dual-drive LiNbO_3 interferometric Mach-Zehnder architecture with extended linear regime for high peak-to-average OFDM-based communication systems. Optics Express. 19 (26), B452-B452

Quinlan, T., Morant, M., Dudley, S., Llorente, R. and Walker, S., (2011). 480Mbit/s UWB bi-directional radio over fiber CWDM PON using ultra-low cost and power VCSELs. Optics Express. 19 (26), B197-B197

Morant, M., Llorente, R., Hauden, J., Quinlan, T., Mottet, A. and Walker, S., (2011). Dual-drive LiNbO_3 interferometric Mach-Zehnder architecture with extended linear regime for high peak-to-average OFDM-based communication systems. Optics Express. 19 (26), B452-B458

Anas, S., Quinlan, T. and Walker, S., (2010). Service differentiated drop code unit for metro ring optical networks. IET Optoelectronics. 4 (1), 46-46

Möllers, I., Parker, M., Morant, M., Librán, I., Walker, S., Jäger, D., Beltrán, M., Mikroulis, S., Karabetsos, S., Llorente, R., Vázquez, C., Montero, D. and Bogris, A., (2010). Radio-over-fibre technologies arising from the Building the future Optical Network in Europe (BONE) project. IET Optoelectronics. 4 (6), 247-259

Parker, MC. and Walker, SD., (2010). A Dynamic Model of Information and Entropy. Entropy. 12 (1), 80-88

Wallace, D., Eltiti, S., Ridgewell, A., Garner, K., Russo, R., Sepulveda, F., Walker, S., Quinlan, T., Dudley, SEM., Maung, S. and others, (2010). Do TETRA (Airwave) base station signals have a short-term impact on health and well-being? A randomized double-blind provocation study. Environmental Health Perspectives. 118 (6), 735-735

Thakur, MP., Quinlan, TJ., Bock, C., Walker, SD., Toycan, M., Dudley, SEM., Smith, DW., Borghesani, A., Moodie, D., Ran, M. and Ben-Ezra, Y., (2009). 480-Mbps, Bi-Directional, Ultra-Wideband Radio-Over-Fiber Transmission Using a 1308/1564-nm Reflective Electro-Absorption Transducer and Commercially Available VCSELs. Journal of Lightwave Technology. 27 (3), 266-272

Ahmad Anas, S., Abdullah, M., Mokhtar, M., Aljunid, S. and Walker, S., (2009). Optical domain service differentiation using spectral-amplitude-coding. Optical Fiber Technology. 15 (1), 26-32

Thakur, MP., Quinlan, T., Bock, C., Walker, S., Toycan, M., Dudley, S., Smith, DW., Borghesani, A., Moodie, D., Ran, M. and Ben-Ezra, Y., (2009). 480-Mbps, Bi-Directional, Ultra-Wideband Radio-Over-Fiber Transmission Using a 1308/1564-nm Reflective Electro-Absorption Transducer and Commercially Available VCSELs. Journal of Lightwave Technology. 27 (3), 266-272

Ahmad-Anas, SB., Abdullah, MK., Mokhtar, M. and Walker, SD., (2008). Multiple access interference elimination with enhanced chromatic dispersion tolerance in SAC OCDMA. IEICE Electronics Express. 5 (16), 617-623

Razavi, R., Hugues-Salas, E., Quinlan, T. and Walker, SD., (2008). Fuzzy logic packet scheduling approach for QoS provision of delay-constrained traffic in synchronous optical packet switched networks. Journal of Optical Networking. 7 (2), 119-119

Dudley, S., Quinlan, T. and Walker, S., (2008). Ultrabroadband Wireless–Optical Transmission Links Using Axial Slot Leaky Feeders and Optical Fiber for Underground Transport Topologies. IEEE Transactions on Vehicular Technology. 57 (6), 3471-3476

Parker, MC. and Walker, SD., (2008). Differential temperature Carnot heat analysis shows that computing machines are thermodynamically irreversible. Optics Communications. 281 (13), 3440-3446

Parker, MC. and Walker, SD., (2007). Is computation reversible?. Optics Communications. 271 (1), 274-277

Toycan, M., Tsalamanis, I., Thakur, M., Walker, SD. and Parker, MC., (2007). Graeco-Latin-routed, self-wrapping, FSR-interleaved, AWG-based access network. Journal of Optical Networking. 6 (6), 654-654

Hugues-Salas, E., Razavi, R., Quinlan, T., Walker, SD. and Parker, MC., (2007). Fast edge-detection burst-mode 2.5Gbit/s receiver for gigabit passive optical networks. Journal of Optical Networking. 6 (5), 482-482

Hisatomi, M., Parker, M. and Walker, S., (2005). Comparison of zoned microstructure fiber geometries for low-dispersion waveguiding. Journal of Lightwave Technology. 23 (2), 558-566

Bock, C., Prat, J. and Walker, S., (2005). Hybrid WDM/TDM PON using the AWG FSR and featuring centralized light generation and dynamic bandwidth allocation. Journal of Lightwave Technology. 23 (12), 3981-3988

Hisatomi, M., Parker, M. and Walker, S., (2005). Binary multi-zoned microstructured fiber: a comparative dispersion analysis of radially chirped Bragg fiber. Journal of Lightwave Technology. 23 (11), 3551-3557

Dudley, S., Guzman, J., Quinlan, T. and Walker, S., (2005). Direct off-air detection, transmission, and tunable bandpass filtering using self-pulsating lasers and substrate antennae. Journal of Lightwave Technology. 23 (2), 809-817

Dudley, S., Quinlan, T., Henning, I., Walker, S., Davey, R., Boyd, I., Wallace, A. and Payne, D., (2005). Ultra-low power, band plan agnostic, hybrid optical∕copper system for last mile access over twisted pair. Electronics Letters. 41 (15), 879-879

Tsalamanis, I., Rochat, E., Parker, M. and Walker, S., (2005). Polarization dependent loss and temperature fluctuations effect on degree of orthogonality in polarization multiplexed arrayed waveguide grating based distribution networks. IEEE Journal of Quantum Electronics. 41 (7), 945-950

Lepley, JJ., Thakur, MP., Tsalamanis, I., Bock, C., Arellano, C., Prat, J. and Walker, SD., (2005). VDSL transmission over a fiber extended-access network. Journal of Optical Networking. 4 (8), 517-517

Parker, MC. and Walker, SD., (2004). Information transfer and Landauer’s principle. Optics Communications. 229 (1-6), 23-27

Rochat, E., Walker, SD. and Parker, MC., (2004). Polarisation and wavelength division multiplexing at 1.55 ?m for bandwidth enhancement of multimode fibre based access networks. Optics Express. 12 (10), 2280-2280

Hisatomi, M., Parker, MC. and Walker, SD., (2004). Zoned microstructure fiber for low-dispersion waveguiding and coupling to photonic crystals. Optics Letters. 29 (10), 1054-1054

Tsalamanis, I., Rochat, E., Walker, SD., Parker, MC. and Holburn, DM., (2004). Experimental demonstration of cascaded AWG access network featuring bi-directional transmission and polarization multiplexing. Optics Express. 12 (5), 764-764

Rochat, E., Walker, S. and Parker, M., (2003). C-band polarisation orthogonality preservation in 5Gb/s, 50µm multimode fibre links up to 3km. Optics Express. 11 (6), 507-507

Dudley, S., Guzman, J., Quinlan, T., Walker, S., Airey, R., Hill, G. and Parker, M., (2003). Tuneable optoelectronic bandpass filtering using a simple self-pulsating two-section laser. Optics Express. 11 (2), 151-151

Tyler, E., Kourtessis, P., Webster, M., Rochart, E., Quinlan, T., Dudley, S., Walker, S., Penty, R. and White, I., (2003). Toward terabit-per-second capacities over multimode fiber links using SCM/WDM techniques. Journal of Lightwave Technology. 21 (12), 3237-3243

Krizhanovskii, DN., Butté, R., Connolly, LG., Tartakovskii, AI., Lidzey, DG., Skolnick, MS. and Walker, S., (2003). Photoluminescence emission and Raman scattering polarization in birefringent organic microcavities in the strong coupling regime. Journal of Applied Physics. 93 (9), 5003-5007

Kourtessis, P., Quinlan, T., Rochat, E., Walker, S., Webster, M., White, I., Penty, R. and Parker, M., (2002). 0.6 Tbit∕s∕km multimode fibre feasibility experiment using 40 channel DWDM over quadrature-subcarrier transmission. Electronics Letters. 38 (15), 813-813

Parker, M. and Walker, S., (2002). Arrayed waveguide gratings, fiber Bragg gratings, and photonic crystals: an isomorphic Fourier transform light propagation analysis. IEEE Journal of Selected Topics in Quantum Electronics. 8 (6), 1158-1167

Parker, M. and Walker, S., (2002). A unified Fourier transform theory for photonic crystal and FBG filters in the strong coupling regime. IEEE Photonics Technology Letters. 14 (9), 1321-1323

Shamim Siddiqui, A., Edirisinghe, S., Lepley, J., Ellison, J. and Walker, S., (2002). Dispersion-tolerant transmission using a duobinary polarization-shift keying transmission scheme. IEEE Photonics Technology Letters. 14 (2), 158-160

Parker, MC. and Walker, SD., (2002). Erratum: A unified Fourier transform theory for photonic crystal and FBG filters in the strong coupling regime (IEEE Photonics Technology Letters (September 2002) 14 (1321-1323)). IEEE Photonics Technology Letters. 14 (12), 1749-1749

Lidzey, DG., Fox, AM., Rahn, MD., Skolnick, MS., Agranovich, VM. and Walker, S., (2002). Experimental study of light emission from strongly coupled organic semiconductor microcavities following nonresonant laser excitation. Physical Review B. 65 (19), 1953121-19531210

Hobson, PA., Barnes, WL., Lidzey, DG., Gehring, GA., Whittaker, DM., Skolnick, MS. and Walker, S., (2002). Strong exciton–photon coupling in a low-Q all-metal mirror microcavity. Applied Physics Letters. 81 (19), 3519-3521

Parker, M., Walker, S. and Mears, R., (2001). An isomorphic Fourier transform analysis of AWGs and FBGs. IEEE Photonics Technology Letters. 13 (9), 972-974

Parker, MC., Mears, RJ. and Walker, SD., (2001). A Fourier transform theory for photon localization and evanescence in photonic bandgap structures. Journal of Optics A: Pure and Applied Optics. 3 (6), S171-S183

Virgili, T., Lidzey, D., Bradley, D. and Walker, S., (2001). Cavity mode polarisation splitting in organic semiconductor microcavities. Synthetic Metals. 116 (1-3), 497-500

Virgili, T., Lidzey, D., Grell, M., Walker, S., Asimakis, A. and Bradley, D., (2001). Completely polarized photoluminescence emission from a microcavity containing an aligned conjugated polymer. Chemical Physics Letters. 341 (3-4), 219-224

Emam-Ismail, M., Lidzey, DG., Skolnick, MS., Bradley, DD., Walker, S., Agranovich, VM. and Tartakovskii, AI., (2001). Raman scattering in strongly coupled organic semiconductor microcavities. Physical Review B - Condensed Matter and Materials Physics. 63 (12), 1213021-1213024

Lepley, J., Ellison, J., Edirisinghe, S., Siddiqui, A. and Walker, S., (2000). Excess penalty impairments of polarisation shift keying transmission format in presence of polarisation mode dispersion. Electronics Letters. 36 (8), 736-736

Parker, M., Walker, S., Yiptong, A. and Mears, R., (2000). Applications of active arrayed-waveguide gratings in dynamic WDM networking and routing. Journal of Lightwave Technology. 18 (12), 1749-1756

Parker, MC. and Walker, SD., (2000). Correction To “A Fourier-fresnel Integral-based Transfer Function Model For A Near-parabolic Phase Profile Arrayed-waveguide Grating”: (IEEE Photonics Technology Letters (1999) 11(8) (1018–1020) (10.1109/68.775332)). IEEE Photonics Technology Letters. 12 (12), 1713-1713

Parker, MC. and Walker, SD., (2000). Comments and Corrections Corrections to “Design of Arrayed-Waveguide Gratings Using Hybrid Fourier-Fresnel Transform Techniques”. IEEE Journal on Selected Topics in Quantum Electronics. 6 (5), 817-817

Fletcher, R., Lidzey, D., Bradley, D., Walker, S., Inbasekaran, M. and Woo, E., (2000). High brightness conjugated polymer LEDs. Synthetic Metals. 111-112, 151-153

Armitage, A., Lidzey, D., Bradley, D., Virgili, T., Skolnick, M. and Walker, S., (2000). Modelling of asymmetric excitons in organic microcavities. Synthetic Metals. 111-112, 377-379

Fletcher, RB., Lidzey, DG., Bradley, DDC., Bernius, M. and Walker, S., (2000). Spectral properties of resonant-cavity, polyfluorene light-emitting diodes. Applied Physics Letters. 77 (9), 1262-1264

Parker, M. and Walker, S., (1999). A Fourier-Fresnel integral-based transfer function model for a near-parabolic phase profile arrayed-waveguide grating. IEEE Photonics Technology Letters. 11 (8), 1018-1020

Parker, M. and Walker, S., (1999). Design of arrayed-waveguide gratings using hybrid Fourier-Fresnel transform techniques. IEEE Journal of Selected Topics in Quantum Electronics. 5 (5), 1379-1384

Parker, MC. and Walker, SD., (1999). Dynamic dispersion compensation using a Fourier-Fresnel phase apertured active arrayed-waveguide grating. LEOS Summer Topical Meeting, 41-42

Sumner, T., Quenby, J., Bewick, A., Smith, N., Jones, W., Ali, T., Ahmed, B., Davidge, D., Davies, G., Howard, A., Joshi, M., Smith, P., Homer, G., Arnison, G., Lewin, J., Alner, G., Spooner, N., Thompson, L., Sellin, P., Walker, S., Roberts, J., Peak, C. and Barton, J., (1999). Current limits on the cold dark matter interaction cross section obtained by the UK collaboration. Nuclear Physics B - Proceedings Supplements. 70 (1-3), 74-78

Lidzey, D., Virgili, T., Bradley, D., Skolnick, M., Walker, S. and Whittaker, D., (1999). Observation of strong exciton–photon coupling in semiconductor microcavities containing organic dyes and J-aggregates. Optical Materials. 12 (2-3), 243-247

Lidzey, DG., Bradley, DDC., Virgili, T., Armitage, A., Skolnick, MS. and Walker, S., (1999). Room Temperature Polariton Emission from Strongly Coupled Organic Semiconductor Microcavities. Physical Review Letters. 82 (16), 3316-3319

Parker, M., Farjady, F. and Walker, S., (1998). Wavelength-tolerant optical access architectures featuring N-dimensional addressing and cascaded arrayed waveguide gratings. Journal of Lightwave Technology. 16 (12), 2296-2302

Parker, MC., Farjady, F. and Walker, SD., (1998). Optimised wavelength-set multi-stage broadband access network employing arrayed-waveguide grating routers. IEE Colloquium (Digest) (257)

Farjady, F., Parker, MC. and Walker, SD., (1998). Non-linear phase apodisation techniques for arrayed-waveguide grating passband control. IEE Colloquium (Digest) (257)

Lidzey, DG., Bradley, DDC., Skolnick, MS., Virgili, T., Walker, S. and Whittaker, DM., (1998). Strong exciton-photon coupling in an organic semiconductor microcavity. Nature. 395 (6697), 53-55

Zhou, J., O'Mahony, M. and Walker, S., (1994). Analysis of optical crosstalk effects in multi-wavelength switched networks. IEEE Photonics Technology Letters. 6 (2), 302-305

Bates, RJS., Walker, SD. and Yaseen, M., (1993). The limits of plastic optical fiber for short distance high-speed computer data links. Fiber and Integrated Optics. 12 (2), 199-208

Bates, R. and Walker, S., (1992). Optical networking and signal-processing applications of 790 nm self-pulsating laser diodes. IEE Proceedings J Optoelectronics. 139 (4), 263-263

Bates, R. and Walker, S., (1992). Evaluation of all-plastic optical fibre computer data link dispersion limits. Electronics Letters. 28 (11), 996-998

Bates, R. and Walker, S., (1991). 450 Mbit/s BPSK and 1 Gbit/s QPSK throughput subcarrier multiple-access networks using 790 nm selfpulsating laser transmitter network for computer applications. Electronics Letters. 27 (12), 1014-1014

Hunter, C., Calton, R., Sadd, P. and Walker, S., (1991). Optical feedback receiver with sensitivity of −55.2 dBm at 8 Mbit/s. Electronics Letters. 27 (10), 886-887

Walker, S., Li, M., Boucouvalas, A., Cunningham, D. and Coles, A., (1990). Design techniques for subcarrier multiplexed broadcast optical networks. IEEE Journal on Selected Areas in Communications. 8 (7), 1276-1284

Walker, SD. and Yaseen, M., (1989). Sampling and downconverting avalanche photodiode receivers for future high-speed optical network applications. Proceedings of SPIE - The International Society for Optical Engineering. 1120, 56-67

Walker, S., Coles, A., Cunningham, D. and Boucouvalas, A., (1989). Maximum loss budget criteria for subcarrier multiplex broadcast passive optical networks. Electronics Letters. 25 (16), 1023-1023

Walker, S., Blank, L., Garnham, R. and Boggis, J., (1989). High electron mobility transistor lightwave receiver for broad-band optical transmission system applications. Journal of Lightwave Technology. 7 (3), 454-458

McNally, B., Carter, S. and Walker, S., (1988). Jitter accumulation in a simulated 591.2 Mbit/s, 6000 km optical transmission system. Electronics Letters. 24 (11), 676-678

Walker, SD. and Garnham, RA., (1987). MID-INFRARED OPTICAL TRANSMISSION SYSTEMS.. British Telecom technology journal. 5 (3), 5-8

Walker, S., Blank, L., Bickers, L. and Garnham, R., (1986). Transmission and signal processing techniques for gigabit lightwave systems. Journal of Lightwave Technology. 4 (7), 759-766

Walker, SD. and Garnham, RA., (1986). Fluoride optical fibre transmission experiments using non-cryogenic sources and detectors. Proceedings of SPIE - The International Society for Optical Engineering. 618, 192-198

Blank, L., Garnham, R. and Walker, S., (1986). 2 Gbit/s and 2.4 Gbit/s optical transmission field trial over a 32 km installed route. Electronics Letters. 22 (1), 33-35

Blank, LC., Bickers, L. and Walker, S., (1986). LONG SPAN OPTICAL TRANSMISSION EXPERIMENTS.. Wire Industry. 53 (630), 446-452

Walker, SD. and Blank, LC., (1986). Progress in long-span, high-capacity optical transmission system research. Proceedings of SPIE - The International Society for Optical Engineering. 630, 9-19

Walker, SD., Blank, LC. and Garnham, RA., (1986). 2. 4 Gbit/s LIGHTWAVE SYSTEM EXPERIMENT.. Wire Industry. 53 (628), 332-333

Blank, L., Bickers, L. and Walker, S., (1985). Long span optical transmission experiments at 34 and 140 Mbit/s. Journal of Lightwave Technology. 3 (5), 1017-1026

Bickers, L., Blank, L. and Walker, S., (1985). Long-span optical transmission experiment over 222.8 km of commercial monomode fibre at 140 Mbit/s and 1.525 μm. Electronics Letters. 21 (7), 267-267

Blank, LC., Bickers, L. and Walker, SD., (1985). LONG SPAN OPTICAL TRANSMISSION EXPERIMENTS AT 34 AND 140 MBIT/S.. Journal of Lightwave Technology. LT-3 (5)

Walker, S., Blank, LC., Bickers, L. and Garnham, R., (1985). TRANSMISSION AND SIGNAL PROCESSING TECHNIQUES FOR GIGABIT LIGHTWAVE SYSTEMS.. Journal of Lightwave Technology. LT-4 (7)

Frisch, D., Bickers, L., Blank, L., Walker, S., Fiddyment, P., Nelson, A. and Westbrook, L., (1984). 565 Mbaud 100 km optical system trial using a ridge waveguide DFB laser at 1.478 μm. Electronics Letters. 20 (7), 300-300

Walker, S. and Blank, L., (1984). Long-wavelength transimpedance optical receiver performance enhancement using cooled germanium avalanche photodiodes. Electronics Letters. 20 (1), 16-16

Frisch, D., Bickers, L., Blank, L., Walker, S., Garnham, R. and Boggis, J., (1984). High-capacity 1.3 μm unrepeatered optical fibre transmission system trials for submarine applications. Electronics Letters. 20 (4), 154-154

Walker, S., Blank, L. and Bickers, L., (1984). 1.8 Gbit/s 65 km optical transmission experiment using a 1.478 μm DFB laser and Ge APD receiver. Electronics Letters. 20 (18), 717-717

Walker, S. and Blank, L., (1984). Ge APD/GaAs FET/op-amp transimpedance optical receiver design having minimum noise and intersymbol interference characteristics. Electronics Letters. 20 (20), 808-808

Book chapters (4)

Canales-Valenzuela, C., Baltatu, M., Costa, L., Habel, K., Jungnickel, V., Koczian, G., Ngobigha, F., Parker, M., Siddiqui, MS., Trouva, E. and Walker, S., (2018). 5G System Design: Architectural and Functional Considerations and Long Term Research: Chapter 9: Security. Editors: Marsch, P., Bulakci, A., Queseth, O. and Boldi, M., . John Wiley & Sons. 207- 225

Adeyemi-Ejeye, A., Koczian, G., Alreshoodi, MA., Parker, M. and Walker, S., (2017). Ultra-High-Definition Video Transmission for Mission-Critical Communication Systems Applications: Challenges and Solutions. Editors: Al-Begain, K. and Ashraf, A., . IGI Global. 115- 115

Musa, IK. and Walker, S., (2014). Multi Objective Optimization Strategy Suitable for Virtual Cells as a Service. In: Innovations in Bio-inspired Computing and Applications. Editors: Abraham, A., Kr�mer, P. and Sn�?el, V., . Springer. 49- 59

André, P., Arellano, C., Bock, C., Bonada, F., Chanclou, P., Fàbrega, JM., Genay, N., Koonen, T., Lazaro, JA., Lepley, J., López, ET., Omella, M., Polo, V., Prat, J., Teixeira, A., Di Bartolo, S., Beleffi, GT. and Walker, SD., (2008). Enhanced transmission techniques. In: Next-Generation FTTH Passive Optical Networks: Research Towards Unlimited Bandwidth Access. 65- 109. 9781402084690

Conferences (204)

Alharbi, Y. and Walker, S., (2018). Virtual machine placement using pre-fetching data transfer

Alarefi, SAS. and Walker, SD., (2018). Empirical investigation and Simulink-simulation modelling of hydropower generator characteristic impedance

Adebomehin, AA. and Walker, SD., (2017). Ultra-wideband signals for high-resolution cognitive positioning techniques in 5G wireless

Quinlan, T. and Walker, S., (2017). A monopole fed omnidirectional 13dBi gain Bi-conical horn antenna for IEEE802.11ad applications

Loukriz, A., Dudley, S., Messalti, S., Quinlan, T., Loukriz, A. and Walker, S., (2017). A novel single-phase thirteen level inverter for photovoltaic application

Adebomehin, AA. and Walker, SD., (2017). Impulse radio Ultrawideband D2D-based localization for ultra-dense 5G networks

Habib, U., Aighobahi, AE., Nair, M., Zhu, H., Quinlan, T., Walker, SD. and Gomes, NJ., (2017). Performance improvement for OFDM-RoF transported 60 GHz system using spatial diversity and multiplexing

Alarefi, SAS. and Walker, S., (2017). Innovative shunt measurement for residential water micro-leakage detection

Loukriz, A., Dudley, S., Brown, R., Quinlan, T. and Walker, S., (2017). Experimental validation of a thirteen level H-bridge photovoltaic inverter configuration

Alharbi, Y. and Walker, S., (2017). Data intensive, computing and network aware (DCN) cloud VMs scheduling algorithm

Parker, MC., Koczian, G., Walker, SD., Habel, K., Jungnickel, V., Rokkas, T., Neokosmidis, I., Siddiqui, MS., Escalona, E., Canales-Valenzuela, C., Foglar, A., Ulbricht, M., Liu, Y., Point, JC., Kritharidis, D., Katsaros, KV., Trouva, E., Angelopoulos, Y., Filis, K., Lyberopoulos, G., Zetserov, E., Levi, D., Kralj, P. and Jenko, P., (2017). Ultra-low latency 5G CHARISMA architecture for secure intelligent transportation verticals

Habib, U., Aighobahi, AE., Quinlan, T., Walker, SD. and Gomes, NJ., (2017). Demonstration of radio-over-fiber-supported 60 GHz MIMO using separate antenna-pair processing

Abe, A. and Walker, SD., (2016). Multi-hop 802.11ad wireless H.264 video streaming

Adebomehin, AA. and Walker, SD., (2016). Enhanced Ultrawideband LOS Suffiency Positioning and Mitigation for Cognitive 5G Wireless Setting

Loukriz, AH., Dudley, S., Quinlan, T. and Walker, SD., (2016). Experimental realization of a single-phase five level inverter for PV applications

Parker, MC., Koczian, G., Adeyemi-Ejeye, F., Quinlan, T., Walker, SD., Legarrea, A., Siddiqui, MS., Escalona, E., Spirou, S., Kritharidis, D., Habel, K., Jungnickel, V., Trouva, E., Kourtis, A., Liu, Y., Sander Frigau, M., Point, JC., Lyberopoulos, G., Theodoropoulou, E., Filis, K., Rokkas, T., Neokosmidis, I., Levi, D., Zetserov, E., Foglar, A., Ulbricht, M., Peternel, B. and Gustincic, D., (2016). CHARISMA: Converged heterogeneous advanced 5G cloud-RAN architecture for intelligent and secure media access

Abe, A. and Walker, SD., (2016). Enhancement of 60GHz transmission over 802.11ad using specular reflection

Adebomehin, AA. and Walker, SD., (2016). Enhanced Ultrawideband methods for 5G LOS sufficient positioning and mitigation

Jungnickel, V., Parker, MC., Riera, JF., Bock, C., Marques, V., Levi, D., Schulz, D., Hilt, J., Habel, K., Del Rosal, LF., Freund, R. and Walker, SD., (2016). Software-defined Open Access for flexible and service-oriented 5G deployment

Domoney, WF., Ramli, N., Alarefi, S. and Walker, SD., (2016). Smart city solutions to water management using self-powered, low-cost, water sensors and apache spark data aggregation

Alarefi, SAS. and Walker, SD., (2016). Intelligent low-cost micro-hydro power emulator for domestic applications

M. Alreshoodi, A. O. Adeyemi-Ejeye, J. Woods, S. D. Walker and J. Pokhrel, (2016). Interval Type-2 Fuzzy Logic Quality prediction model for wireless 4kUHD H.265-coded video streaming

Ramli, N. and Walker, S., (2016). Power maximization using multiple step, load-side, current-mode sensing

Ramli, N. and Walker, S., (2016). Pan-global, annualized determination of solar collector optimum tilt angle

Parker, MC., Koczian, G., Quinlan, T. and Walker, SD., (2015). High capacity communications at 24 GHz and 60 GHz for converged 5G networking

Ramli, NM., Alarefi, SAS. and Walker, SD., (2015). Renewable power and microgeneration in Libya: Photovoltaic system sizing, wind, rainfall potentials and public response

Corsatea, BM. and Walker, S., (2015). Opportunities for Moodle data and learning intelligence in Virtual Environments

Alshahrani, AM. and Walker, S., (2015). An encryption algorithm (T-key) based on a 4D tesseract

Alshahranil, AM. and Walker, S., (2015). Tesseract: A 4D symmetric key container for multimedia security

Alshahrani, AMS. and Walker, S., (2015). Inventive Cubic symmetric encryption system for multimedia

Alshahrani, AMS. and Walker, S., (2015). An encryption algorithm (T-key) based on a 4D tesseract

Bock, C., Ferrer, J., Parker, MC., Walker, SD., Mendes, T., Marques, V., Jungnickel, V., Habel, K. and Levi, D., (2014). Techno-economics and performance of convergent radio and fibre architectures

Riera, JF., Bock, C., Escalona, E., Jungnickel, V., Habel, K., Parker, MC., Walker, S., Quinlan, T., Marques, V. and Levi, D., (2014). Software-defined wired-wireless access network convergence: The SODALES approach

Jungnickel, V., Habel, K., Parker, M., Walker, S., Bock, C., Riera, JF., Marques, V. and Levi, D., (2014). Software-defined open architecture for front- and backhaul in 5G mobile networks

Alshahrani, AM. and Walker, S., (2014). A novel encryption solution for real time applications

Quinlan, T. and Walker, S., (2014). A 16.8dBi quasi-discoidal radiation pattern antenna array for 60GHz non-line-of-sight applications

Parker, MC., Jungnickel, V. and Walker, S., (2014). 5G mm-wave and optical wireless links for converged multi-Gb/s access and beyond

Clift, L., Kockzian, G., Adeyemi-Ejeye, AO., Walker, S. and Clark, AF., (2014). Delivering Live 4K Broadcasting Using Today?s Technology

Ferrer, J., Bock, C., Mendes, T., Parker, MC., Jungnickel, V., Levi, D., Marques, V., Rodrigues, C., Escalona, E., Garcia-Espin, JA. and Walker, S., (2014). Techno Economics and Cost Analysis of Convergent Access Networks

Musa, IK. and Walker, SD., (2013). Adaptive market place for converged cloud computing model

Ramli, NM. and Walker, SD., (2013). First realisation of a Golomb ruler staircase inverter for photovoltaic applications

Bock, C., Figuerola, S., Parker, MC., Walker, SD., Mendes, T., Marques, V., Jungnickel, V., Habel, K. and Levi, D., (2013). Convergent radio and fibre architectures for high-speed access

Adeyemi-Ejeye, AO. and Walker, SD., (2013). Ultra-high definition Wireless Video transmission using H.264 over 802.11n WLAN: Challenges and performance evaluation

Alshahrani, AM. and Walker, S., (2013). NFC performance in mobile payment service compared with a SMS -based solution

Quinlan, T. and Walker, S., (2013). A 60GHz, linearly polarised, 16dBi coaxial slot array antenna

Llorente, R., Morant, M., Pellicer, E., Herman, M., Nagy, Z., Alves, T., Cartaxo, A., Herrera, J., Correcher, J., Quinlan, T., Walker, S., Rodrigues, C., Cluzeaud, P., Schmidt, A., Piesiewicz, R. and Sambaraju, R., (2013). On-the-field demonstration of quintuple-play service provision in long-reach OFDM-based WDM-PON access networks

Llorente, R., Morant, M., Pellicer, E., Herman, M., Nagy, Z., Herrera, J., Correcher, J., Alves, T., Cartaxo, A., Quinlan, T., Walker, S., Rodrigues, C., Cluzeaud, P., Schmidt, A., Sambaraju, R., Piesiewicz, R. and Rico, E., (2013). Radio-over-fiber quintuple-play service provision for deep fiber-to-the-home passive networks

Parker, MC. and Walker, SD., (2012). Energy-efficiency optimised upgrade paths for cascaded, stochastically-based, master-slave IP router configurations

Parker, MC. and Walker, SD., (2012). Energy-efficiency optimised upgrade paths for cascaded, stochastically-based, master-slave IP router configurations

Parker, MC., Martin, R., Walker, SD., Van Heddeghem, W. and Lannoo, B., (2012). Energy-efficient master-slave edge-router upgrade paths in active remote nodes of next-generation optical access

Ejeye, AO. and Walker, SD., (2012). Uncompressed quad-1080p wireless video streaming

Bock, C., Figuerola, S., Parker, MC., Quinlan, T. and Walker, SD., (2012). Convergent radio and fibre access architectures using low-energy systems

Parker, MC. and Walker, SD., (2012). Stochastic energy-efficiency optimization in photonic networking by use of master-slave equipment configurations

Quinlan, T., Dudley, S., Morant, M., Llorente, R. and Walker, S., (2012). First Demonstration of cooler-Less, Bi-Directional, format-Agnostic, wireless and gigabit ethernet network provision using Off-The-Shelf VCSELs

Hugues-Salas, E., Giddings, RP., Jin, XQ., Quinla, T., Hong, Y., Walker, S. and Tang, JM., (2012). REAM intensity modulator-enabled colorless transmission of real-time optical OFDM signals for WDM-PONs

Mahmouli, FE. and Walker, S., (2012). Orbital angular momentum generation in a 60GHz wireless radio channel

Quinlan, T., Warren, N. and Walker, S., (2012). A 1.5 GHz bandwidth, linear polarisation switchable, 5 GHz crossed rectangular patch antenna

Llorente, R., Morant, M., Martínez, F., Alves, T., Cartaxo, A., Quinlan, T., Walker, S., Rodrigues, C., Herrera, J., Cluzeaud, P., Schmidt, A., Sambaraju, R., Rico, E., Piesiewicz, R. and Herman, M., (2012). Impairment compensation in long-reach integrated optical-wireless PON

Hugues-Salas, E., Giddings, RP., Jin, XQ., Quinlan, T., Hong, Y., Walker, S. and Tang, JM., (2012). REAM intensity modulator-enabled colorless transmission of real-time optical OFDM signals for WDM-PONs

Parker, MC., Martin, R., Guild, K. and Walker, SD., (2011). Hierarchical wireless and optical access networking: Convergence and energy efficiency

Mitchell, JE., Thakur, MP., Parker, MC. and Walker, SD., (2011). Radio-over-fibre networks: Developments from the BONE Virtual Centre of Excellence in Access

Kaka, A., Toycan, M., Bashiry, V., Ademgil, H. and Walker, SD., (2011). A fractal geometry, multi-band, miniaturized monopole antenna design for UWB wireless applications

Morant, M., Quinlan, T., Walker, S. and Llorente, R., (2011). "Real world" FTTH optical-to-radio interface performance for bi-directional multi-format OFDM wireless signal transmission

Morant, M., Quinlan, T., Ng'oma, A., Dudley, S., Walker, S. and Llorente, R., (2011). Specialty fiber evaluation for in-building distribution of multiple-format OFDM radio signals

Morant, M., Quinlan, T., Walker, S. and Llorente, R., (2011). Complete mitigation of brillouin scattering effects in reflective passive optical networks using triple-format OFDM radio signals

Morant, M., Quinlan, T., Llorente, R. and Walker, S., (2011). Full standard triple-play bi-directional and full-duplex CWDM transmission in passive optical networks

Morant, M., Quinlan, T., Ng'oma, A., Dudley, S., Walker, S. and Llorente, R., (2011). Specialty fiber evaluation for in-building distribution of multiple-format OFDM radio signals

Morant, M., Quinlan, T., Walker, S. and Llorente, R., (2011). Complete mitigation of brillouin scattering effects in reflective passive optical networks using triple-format OFDM radio signals

Llorente, R., Morant, M., Hauden, J., Quinlan, T., Mottet, A. and Walker, S., (2011). Linear regime extension technique in parallel LiNbO3 interferometric architectures for UWB applications

Quinlan, T., Morant, M., Llorente, R. and Walker, S., (2011). Ultra-low cost and power VCSEL-based 480Mbit/s UWB radio over a bi-directional CWDM PON

Llorente, R., Morant, M., Hauden, J., Quinlan, T., Mottet, A. and Walker, S., (2011). Linear regime extension technique in parallel LiNbO3 interferometric architectures for UWB applications

Quinlan, T., Dudley, S., Jordan, T. and Walker, S., (2011). Remote, non-contact, radio frequency phase contrast detection using CWDM and directly modulated VCSELs

Quinlan, T., Morant, M., Llorente, R. and Walker, S., (2011). Ultra-low cost and power VCSEL-based 480Mbit/s UWB radio over a bi-directional CWDM PON

Llorente, R., Morant, M., Quinlan, T., Medina, N. and Walker, S., (2011). Optical architectures evaluation for triple-play distribution in FIVER project

Morant, M., Quinlan, T., Llorente, R. and Walker, S., (2011). Full standard triple-play bi-directional and full-duplex CWDM transmission in passive optical networks

Morant, M., Quinlan, T., Walker, S. and Llorente, R., (2011). "Real world" FTTH optical-to-radio interface performance for bi-directional multi-format OFDM wireless signal transmission

Morant, M., Quinlan, T., Walker, S. and Llorente, R., (2011). Complete mitigation of brillouin scattering effects in reflective passive optical networks using triple-format OFDM radio signals

Morant, M., Quinlan, T., Ng'oma, A., Dudley, S., Walker, S. and Llorente, R., (2011). Specialty fiber evaluation for in-building distribution of multiple-format OFDM radio signals

Moreb, SA. and Walker, SO., (2011). Server farms' power consumption minimized via best allocation of servers and ancillary equipments

Llorente, R., Walker, S., Monroy, IT., Beltrán, M., Morant, M., Quinlan, T. and Jensen, JB., (2011). Triple-play and 60-GHz radio-over-fiber techniques for next-generation optical access networks

Quinlan, TJ., Dudley, SEM. and Walker, SD., (2010). Radio-over-fibre phase contrast imaging using a reflective electro-absorption transducer and 1550/1310nm VCSELs

Quinlan, TJ., Dudley, SEM. and Walker, SD., (2010). Radio-over-fibre phase contrast imaging using a reflective electro-absorption transducer and 1550/1310nm VCSELs

Thakur, MP., Mitchell, JE., Quinlan, TJ., Parker, MC. and Walker, SD., (2010). First demonstration of secure, AWG performance interrogation using OFDM edge-tones on WDM access networks

Quinlan, TJ., Dudley, SEM. and Walker, SD., (2010). Radio-over-fibre phase contrast imaging using a reflective electro-absorption transducer and 1550/1310nm VCSELs

Thakur, MP., Quinlan, T., Ahmad Anas, SB., Hunter, DK., Walker, SD., Smith, DW., Borghesani, A. and Moodie, D., (2009). Multi-wavelength, 4.32 Gbps UWB radio-over-fiber demonstration featuring a reflective electro-absorption transceiver and low-Cost DWDM grid VCSELs

Thakur, MP., Quinlan, T., Ahmad Anas, SB., Hunter, DK., Walker, SD., Smith, DW., Borghesani, A. and Moodie, D., (2009). Triple-Format, UWB-WiFi-WiMax, Radio-Over-Fiber Co-Existence Demonstration Featuring Low-Cost 1308/1564 nm VCSELs and a Reflective Electro-Absorption Transceiver

Bock, C., Quinlan, T., Thakur, MP. and Walker, SD., (2009). Integrated Optical Wireless Access: Advanced topologies for future access networks

Parker, MC., Nagraj, S. and Walker, SD., (2009). Absolute energy efficiency metric for carbon footprint resource management and network optimisation

Walker, S., Quinlan, T., Dudley, S., Jordan, T. and Parker, M., (2009). Wireless broadband service delivery via optical in-home converged networks

Quinlan, T., Dudley, S., Jordan, T. and Walker, S., (2009). Improved radio frequency imaging resolution using phase contrast interferometry

Llorente, R., Morant, M., Tokle, T., Quinlan, T., Thakur, M. and Walker, S., (2009). UWB radio-over-fiber and photonic sensing for cognitive optical access networks

Smith, DW., Borghesani, A., Moodie, D., Thakur, MP., Quinlan, T., Dudley, S., Toycan, M., Bock, C., Walker, SD., Ran, M. and Ben-Ezra, Y., (2008). 480Mbps ultra-wideband radio-over-fibre transmission using a 1310/1550nm reflective electro-absorption transducer and off-the-shelf components

Bock, C., Thakur, MP., Quinlan, T., Dudley, SEM. and Walker, SD., (2008). Integration of wireless and optics, future trends on access networks

Thakur, MP., Quinlan, T., Dudley, S., Toycan, M., Bock, C., Walker, SD., Smith, DW., Borghesani, A., Moodie, D., Llorente, R., Ran, M. and Ben-Ezra, Y., (2008). Bi-directional, 480Mbps, ultra-wideband, radio-over-fibre transmission using a 1310/1564nm reflective electro-absorption transducer and commercially-available components

Llorente, R., Thakur, MP., Morant, M., Walker, SD. and Marti, J., (2008). Performance comparison of radio-over-fibre UWB distribution in SSMF and MMF optical media

Nezami, KG., Stephens, PW. and Walker, SD., (2008). Handel-C implementation of Early-Access Partial-Reconfiguration for Software Defined Radio

Ajmal, T., Quinlan, T., Razavi, R., Salas, EH. and Walker, SD., (2008). Design of a 10Gbps optical burst mode DPSK receiver for data and clock recovery

Nezami, KG., Stephens, PW. and Walker, SD., (2008). Computationally-efficient, low-order filtering technique for TETRA Release 2 synchronization

Ben-Ezra, Y., Ran, M., Borohovich, E., Leibovich, A., Thakur, MP., Llorente, R. and Walker, SD., (2008). Wimedia-defined, ultra-wideband radio transmission over optical fibre

Quinlan, TJ., Dudley, SEM. and Walker, SD., (2008). Time-resolved bragg effects in an ultra wideband leaky feeder antenna array based on semi-rigid coaxial cable

Ajmal, T. and Walker, S., (2008). 1.562 Gb/s phase-encrypted secure communication

Mokhtar, M., Quinlan, T., Walker, SD., Abas, AF. and Abdulllah, MK., (2008). A new RZ/NRZ bipolar code

Toycan, M., Thakur, MP. and Walker, SD., (2007). Optical network architecture for UWB range extension beyond a single complex of cells

Bock, C., Prat, J. and Walker, SD., (2007). Flexible and scalable high-density quad-play packet-switched access infrastructure based on WDM routing and dynamic TDM access

Hugues-Salas, E., Razavi, R., Quinlan, TJ., Thakur, MP. and Walker, SD., (2007). A 2.5 Gb/s edge-detecting burst-mode receiver for GPON access networks

Walker, SD., Toycan, M., Tsalamanis, I. and Parker, MC., (2007). A FSR-interleaved, self-wrapping, multiple-cascaded AWG-based WDM access network

Walker, SD., Toycan, M., Tsalamanis, I. and Parker, MC., (2007). A FSR-interleaved, self-wrapping, multiple-cascaded AWG-based WDM access network

Quinlan, TJ., Dudley, SEM. and Walker, SD., (2007). A high data rate wireless leaky feeder system for vehicular tunnel applications

Hugues-Salas, E., Razavi, R., Quinlan, TJ., Thakur, MP. and Walker, SD., (2007). A 2.5 Gb/s edge-detecting burst-mode receiver for GPON access networks

Kourtessis, P. and Walker, SD., (2007). A Complete 8-GHz QPSK-MODEM Featuring Novel Subcarrier and Data Synchronization for Optical Communications

Walker, SD., Toycan, M., Tsalamanis, I. and Parker, MC., (2007). A FSR-interleaved, self-wrapping, multiple-cascaded AWG-based WDM access network

Nezami, KG., Stephens, PW. and Walker, SD., (2007). Enhanced communications firmware platform for co-verification of complex algorithms

Dudley, SEM., Quinlan, TJ. and Walker, SD., (2007). 1.6Gb/s data throughput optically-remoted leaky feeders for underground transport environments

Bock, C., Prat, J. and Walker, SD., (2007). Optical next-generation access networks featuring combined WDM and TDM

Ajmal, T., Hugues-Salas, E., Razavi, R., Quinlan, T., Zervas, G., Simeonidou, D. and Walker, SD., (2007). Phase-encrypted secure communication technique for GPONs

Nezami, KG., Walker, SD., Stephens, PW. and Fleury, M., (2006). An FPGA implementation of a memory efficient, low complexity turbo decoder architecture for TETRA release 2 application

Thakur, MP., Tsalamanis, I., Lepley, JJ. and Walker, SD., (2006). VDSL transmission over latin routed DWDM optical access networks

Dudley, SEM., Quinlan, T., Henning, ID., Walker, SD., Davey, RP., Payne, DB. and Boyd, I., (2006). Ultra low power optical feeder for VDSL

Hisatomi, M., Parker, MC. and Walker, SD., (2006). Waveguiding of orbital angular momentum light using chiral-selectivity azimuthally graded index fibre

Ajmal, T., Lepley, JJ. and Walker, SD., (2006). Experimental demonstration of a macroscopic cryptography technique

Mokhtar, M., Abdullah, MK. and Walker, SD., (2006). Towards ternary optical communication by soft decoding

Ajmal, T., Lepley, JJ. and Walker, SD., (2006). Stokes encrypted secure communication over optically amplified links

Tsalamanis, I., Toycan, M. and Walker, SD., (2006). Study of hybrid cascaded AWG-based access network topology

Lepley, J., Thakur, MP., Tsalamanis, I., Walker, SD., Habel, K., Langer, KD., Rijckenberg, GJ., Ng'oma, A., Koonen, AMJ. and Wellen, JS., (2006). Interoperability of Last Mile access technologies over a passive optical ring network: results of the MUSE Demonstration

Parker, MC., Hisatomi, M. and Walker, SD., (2006). Hollow-core radially-chirped Bragg fiber for quasi-metallic photonic bandgap light confinement

Bock, C., Prat, J. and Walker, SD., (2006). High-density optical burst switched access network combining WDM and TDM over a passive optical infrastructure

Dudley, S., Quinlan, T., Henning, I., Walker, S., Davey, R., Wallace, A., Boyd, I. and Payne, D., (2006). Low-power optical feeder for VDSL over twisted pair for last mile access networks

Bock, C., Prat, J. and Walker, SD., (2006). High-density ring-tree advanced access topology delivering bandwidth on demand over a resilient infrastructure

Parker, MC., Hunter, DK. and Walker, SD., (2006). Tunable optical delays, buffering and WDM:TDM conversion via active Latin-routing AWG's featuring unit-length re-circulating waveguides

Wellen, J., Smets, R., Hellenthal, W., Lepley, J., Tsalamanis, I., Walker, S., Ng'oma, A., Rijckenberg, GJ., Koonen, T., Habel, K. and Langer, KD., (2006). Towards high speed access technologies: Results from MUSE

Prat, J., Chanclou, P., Davey, R., Finochietto, JM., Franzl, G., Koonen, AMJ. and Walker, S., (2006). Long-term evolution of passive optical networks

Mokhtar, M., Abdullah, MK., Walker, SD. and IEEE, (2006). Towards Ternary Optical Communication by Soft Decoding

Thakur, MP., Bock, C., Lepley, JJ., Tsalamanis, I., Arellano, C., Prat, J. and Walker, SD., (2005). Passive VDSL transmission over single fibre using reflective technique at customer premises

Bock, C., Thakur, MP., Arellano, C., Lepley, JJ., Tsalamanis, I., Walker, SD. and Prat, J., (2005). Wavelength independent RSOA-based ONU for FTTH PON implementation of switched ethernet services

Thakur, MP., Tsalamanis, I., Lepley, JJ. and Walker, SD., (2005). VDSL transmission over latin routed DWDM optical access networks

Hisatomi, M., Parker, MC. and Walker, SD., (2005). Waveguiding of orbital angular momentum light using chiral-selectivity azimuthally graded index fibre

Thakur, MP., Tsalamanis, I., Lepley, JJ. and Walker, SD., (2005). VDSL transmission over latin routed DWDM optical access networks

Dudley, SEM., Quinlan, T., Henning, ID., Walker, SD., Davey, RP., Payne, DB. and Boyd, I., (2005). Ultra low power optical feeder for VDSL

Hisatomi, M., Parker, MC. and Walker, SD., (2005). Singular optical fibre featuring refractive index dislocation for chiral waveguiding of high orbital angular momentum light

Thakur, MP., Bock, C., Prat, J. and Walker, SD., (2005). Upgrade paths from VDSL-based FTTC to ethernet-based FTTH: An experimental comparison

Thakur, MP., Bock, C., Lepley, JJ., Arellano, C., Prat, J. and Walker, SD., (2005). VDSL over fibre access network with reflective optical network unit

Thakur, MP., Tsalamanis, I., Lepley, JJ. and Walker, SD., (2005). VDSL transmission over latin routed DWDM optical access networks

Hisatomi, M., Parker, MC. and Walker, SD., (2005). Waveguiding of orbital angular momentum light using chiral-selectivity azimuthally graded index fibre

Hunter, DK., Andonovic, I., Parker, MC. and Walker, S., (2005). Delay-line storage in optical communications switching

Tsalamanis, I., Rochat, E., Walker, SD. and Parker, MC., (2004). Polarization orthogonality preservation in DWDM cascaded arrayed-waveguide grating networks

Tsalamanis, I., Rochat, E., Walker, SD. and Parker, MC., (2004). Polarization orthogonality preservation in DWDM cascaded arrayed-waveguide grating networks

Lin, FC., Lalithambika, VA., Holburn, DM., Mears, RJ., Hum, CH. and Walker, SD., (2004). Fully integrated CMOS VCSEL driver with nonlinearity suppression for RF optical fibre links

Lin, FC., Holburn, DM., Lalithambika, VA., Mears, RJ., Hum, CH. and Walker, SD., (2004). A CMOS analogue predistortion circuit for wideband optical fibre links

Hisatomi, M., Parker, MC. and Walker, SD., (2003). Low refractive-index-contrast Fresnel-microstructure fibre for coupling between SMF and photonic crystals

Parker, MC., Rochat, E. and Walker, SD., (2003). Polarisation mode dispersion as Anderson photon localisation: A new interpretation based on the first Born approximation

Rochat, E., Walker, SD. and Parker, MC., (2003). Investigation of combined wavelength and polarisation division multiplexing in C-band over 50 μm multimode fibre links up to 3 km

Parker, M., (2003). An isomorphic Fourier transform approach to light propagation in AWGs, FBGs, and photonic crystals

Lalithambika, VA., Lin, FC., Holburn, DM., Mears, RJ., Hum, CH. and Walker, SD., (2003). Simulation study of BER and signal-to-noise ratio of a multi-channel optical sub-carrier modulated QAM-VDSL signals

Dudley, SEM., Guzman, JM., Quinlan, TJ., Walker, SD. and Parker, MC., (2003). Tunable Optoelectronic Bandpass Filter using a Simple Self-Pulsating Two-Section Laser

Rochat, E., Kourtessis, P., Webster, M., Quinlan, T., Dudley, S., Walker, SD., Penty, RV., Parker, MC. and White, IH., (2002). Ultra-high capacity transmission over 3km of legacy 50μm-multimode-fibre using C-band HDWDM and quadrature-subcarrier multiplexing

Rochat, E., Walker, SD. and Parker, MC., (2002). Ultra-wideband capacity enhancement of 50 μm multimode fibre links up to 3km using orthogonal polarisation transmission in C-band

Penty, RV., Webster, M., White, IH., Kourtessis, P., Walker, SD. and Tyler, EJ., (2002). The applications of SCM in optical data communications

Parker, MC., Rochat, E. and Walker, SD., (2002). All-order PMD compensation using filter theory interpretation of Poincaré Sphere trajectories

Kourtessis, P., Dudley, S., Quinlan, T., Walker, SD., Tyler, EJ., Penty, RV. and White, IH., (2002). A complete 5 Gb/s throughput quadrature subcarrier system featuring zero-latency carrier and data synchronization

Parker, MC. and Walker, SD., (2002). An Isomorphic Fourier Transform Approach to Light Propagation in AWGs, FBGs, and Photonic Crystals

Lidzey, D., Tartakovskii, A., Emam-Ismail, M., Skolnick, M. and Walker, S., (2002). Enhanced Raman scattering in a strongly coupled microcavity containing J-aggregates

Siddiqui, AS., Edirisinghe, SG., Lepley, JJ., Ellison, JG. and Walker, SD., (2001). Dispersion tolerant transmission using a duobinary encoded polarization shift keying modulation format

Parker, M. and Walker, S., (2001). Multiple-order adaptive dispersion compensation using polynomially-chirped grating devices

Parker, MC. and Walker, SD., (2001). Multiple-order PMD compensation using a single actively chirped AWG

Parker, MC. and Walker, SD., (2001). Non-linearly chirped arrayed-waveguide grating configuration for third-order adaptive dispersion compensation

Parker, MC. and Walker, SD., (2001). Optimisation of polyphase concatenated arrayed-waveguide grating designs for 40Gb/s adaptive dispersion compensation

Lidzey, D., Bradley, D., Skolnick, M. and Walker, S., (2001). Optical coupling of Frenkel excitons in organic semiconductor microcavities

Parker, MC. and Walker, SD., (2000). Adaptive chromatic dispersion controller based on an electro-optically chirped arrayed-waveguide grating

Parker, MC., Walker, SD., OSA and OSA, (2000). Virtually ripple-free, 20Gb/s DWDM, adaptive dispersion compensator based on a re-multiplexing concatenated AWG configuration

Parker, MC. and Walker, SD., (1999). Bandpass filter transfer characteristic of a complex-Apodized arrayedwaveguide Grating

Parker, MC. and Walker, SD., (1999). Recent advances in arrayed-waveguide gratings and their application in optical networks

Farjady, F., Parker, MC. and Walker, SD., (1998). Phase apodization techniques for active passband control of arrayed waveguide grating optical routers

Farjady, F., Parker, MC. and Walker, SD., (1998). Non-linear phase apodization techniques for arrayed-waveguide grating passband control

Parker, MC., Farjady, F. and Walker, SD., (1998). Arrayed-waveguide grating passband flattening by combined phase and amplitude apodisation

Parker, MC., Farjady, F. and Walker, SD., (1998). Lightwave communications and networks

Parker, MC., Farjady, F. and Walker, SD., (1998). Passband-flattened arrayed-waveguide grating design using an aspheric output star coupler

Parker, MC., Farjady, F. and Walker, SD., (1998). Optimized wavelength-set multi-stage broadband access network employing arrayed-waveguide grating routers

Farjady, F., Parker, MC. and Walker, SD., (1998). Novel two-stage wavelength-routed access architecture employing spectral-grooming and replicated arrayed waveguide gratings

Parker, MC., Farjady, F. and Walker, SD., (1998). Reduced wavelength-count vector-addressed multi-stage access network based on phased-array optical routers

Parker, MC., Farjady, F. and Walker, SD., (1998). Reduced wavelength-count multi-stage ATM access network featuring voltage-controlled phased-array optical routers

Farjady, F., Parker, MC. and Walker, SD., (1998). Evolutionary multi-dimensional access architecture featuring cost-reduced components

Parker, MC., Farjady, F. and Walker, SD., (1998). Quasi-cycloidal phase profile synthetic aperture technique for passband-broadened arrayed-waveguide gratings

Farjady, F., Parker, MC. and Walker, SD., (1998). High usage optical access architecture featuring coarse space-wavelength routing

Parker, MC., Farjady, F. and Walker, SD., (1998). Passband-flattened arrayed-waveguide grating featuring a new aspheric output star coupler

Farjady, F., Parker, MC. and Walker, SD., (1998). An evolutionary access network upgrade path based on a multi-dimensional time-space-wavelength architecture

Bebbington, DHO., Ellison, JG., Schuh, RE., Shan, X., Siddiqui, AS. and Walker, SD., (1997). Fully polarimetric optical time-domain reflectometer with 1-m spatial resolution

Walker, SD. and NETWORKS, EIC., (1995). Cost-effective customer laser transmitter for burst-mode ATM application

Li, M. and Walker, SD., (1994). Performance of a multichannel global queue cyclic reservation protocol for laser-switched subcarrier multiplexed passive star networks

Yaseen, M. and Walker, SD., (1991). Optoelectronic sampling receiver for time-division multiplexed signal processing applications

Walker, SD., Boucouvalas, AC., Cunningham, DG. and Coles, A., (1990). New pseudorandom sequence measurement technique for subcarrier multiplexed distribution networks

Bates, RJS. and Walker, SD., (1990). 450Mb/s throughput subcarrier multiple-access network using 790NM self-pulsating laser transmitters

Walker, SD., (1989). Optoelectronic phase-locked-loop downconverter for subcarrier AM and FM transmission systems

Walker, SD., (1989). Reflective dispersion measurement technique for high-capacity optical networks

Mallett, CT., Walker, SD. and Fletcher, I., (1988). Synchronous electronic networking of undersea lightwave systems: the impact on repeater and multiplex design and performance.

Carter, SF., Fletcher, I., McNally, BI., Walker, SD. and Blank, LC., (1988). High-speed optical regenerator chain simulation by jitter synthesis.

Blank, LC. and Walker, SD., (1988). High-capacity lightwave transmission systems.

Blank, LC., Boggis, JM., Garnham, RA. and Walker, SD., (1987). HIGH-ELECTRON-MOBILITY TRANSISTOR LIGHTWAVE RECEIVER FOR BROADBAND OPTICAL TRANSMISSION SYSTEM APPLICATIONS.

Walker, SD., Stallard, WA. and Garnham, RA., (1987). LONG-SPAN OPTICAL FIBRE TRANSMISSION SYSTEMS IN THE 2-4 MICRON WAVELENGTH REGION.

Walker, SD. and Garnham, RA., (1986). HIGH SENSITIVITY PHOTORECEIVER FOR MID-INFRA-RED TRANSMISSION SYSTEM APPLICATIONS UP TO 3. 4 MICRON WAVELENGTH.

Bickers, L., Walker, SD. and Blank, LC., (1985). FULLY-REGENERATED 2 GBIT/S, 90 km OPTICAL TRANSMISSION SYSTEM USING A COMMERCIAL GaAs MASTER-SLAVE D-TYPE FLIP-FLOP.

Blank, LC., Bickers, L. and Walker, SD., (1985). 120-Gbit multiplied by (times) km LIGHTWAVE SYSTEM EXPERIMENTS USING 1,478- mu m AND 1. 52- mu m DISTRIBUTED FEEDBACK LASERS.

Walker, SD., Blank, LC. and Bickers, L., (1985). DESIGN AND PERFORMANCE ASPECTS OF HIGH CAPACITY, UNREPEATERED OPTICAL TRANSMISSION SYSTEMS.

Walker, SD., Bickers, L. and Blank, LC., (1984). 1 Gbit/s OPTICAL TRANSMISSION EXPERIMENT OVER 83 km USING A 1. 478 mu m DFB LASER.

Frisch, DA., Bickers, L., Blank, LC. and Walker, SD., (1984). LONG-SPAN UNREPEATERED OPTICAL SYSTEMS.

Grants and funding

2016

67% - To design and develop embedded systems and peripherals for control and monitoring applications making best use of available communications and microprocessor technologies and to embed knowledge of communications and associated sofware technologies.

Technology STrategy Board

33% - To design and develop embedded systems and peripherals for control and monitoring applications making best use of available communications and microprocessor technologies and to embed knowledge of communications and associated sofware technologies.

Dicam Technologies

Mobile Phone Repeater System

LPA Connection System

67% To embed a novel wireless ethernet capability across the rail network, to support innovation in train to shore communication speed and establish LPA as a leading innovator in the sector. To increase the bandwidth of on-board copper Ethenet Backbones

Technology STrategy Board

33% To embed a novel wireless ethernet capability across the rail network, to support innovation in train to shore communication speed and establish LPA as a leading innovator in the sector. To increase the bandwidth of on-board copper Ethenet Backbones

LPA Group PLC

2015

CHARISMA

European Commission (H2020)

Sending data over railway power lines

Network Rail

2014

NIRVANA - iNtelligent, heteRogeneous VirtAlised Networking infrAstructure

Engineering & Physical Sciences Res.Council

iCIRRUS - intelligent Converged network conoLIdating Radio and optical access aRound USER equipment

European Commission (H2020)

2012

SODALES - Software-Defined Access using Low-Energy Subsystems

European Commission

To enable LPA to design rail connectors suitable for RF (67%)

Technology STrategy Board

To enable LPA to design rail connectors suitable for RF (33%)

LPA Industries Ltd

2011

IMPACT

Technology STrategy Board

2010

STRONGEST

European Commission (FP7)

2009

Roadmap Project

Technology STrategy Board

Photonics 21

Technology STrategy Board

OASE Project

European Commission

FIVER

European Commission (FP7)

Contact

stuwal@essex.ac.uk
+44 (0) 1206 872413

Location:

1NW.3.16, Colchester Campus

Academic support hours:

By appointment