Full Standard Triple-Play Bi-Directional and Full-Duplex CWDM Transmission in Passive Optical Networks Maria Morant (1) , Terence Quinlan (2) , Roberto Llorente (1) and Stuart Walker (2) (1) Nanophotonics Technology Centre, Universidad Politécnica de Valencia, Spain (mmorant@ntc.upv.es, rllorent@ntc.upv.es) (2) School of Computer Science and Electronic Engineering, University of Essex, UK (quinlan@essex.ac.uk, stuwal@essex.ac.uk) Abstract: Bi-directional CWDM radio-over-fiber transmission of triple-format full-standard OFDM signals in coexistence (UWB, WiMAX and LTE) (1.178 Gbit/s full-duplex) is demonstrated over 50.6 km SSMF in passive optical networks without amplification or regeneration stages OCIS codes: (060.0060) Fiber optics and optical communications; (060.1155) All-optical networks 1. Introduction Orthogonal frequency division multiplexing (OFDM) signals are incorporated in radio standards such as UWB, WiMAX, LTE, WLAN, DVB-T or DAB. These formats take advantage of the intrinsic characteristics of OFDM modulation such as relative immunity to multi-path fading. This paper proposes and demonstrates multi-format bi- directional radio-over-fiber transmission of triple-play services (3-PLAY) using OFDM-based UWB (for high- definition television), WiMAX (for internet data) and LTE (telephone service) in coexistence over passive optical networks (PON). This technique permits an increase in the overall capacity of the system; providing for triple-play services. Radio-over-fiber transmission allows using standard equipment at both ends of the architecture like low- cost UWB receivers [1], mobile devices using LTE and equipment using in-built WiMAX receivers. Bi-directional, full-duplex transmission is achieved with coarse wavelength division multiplexing (CWDM) [2] using two simultaneous paths in opposite directions at 1300 and 1550 nm. Opportunities for PON network spans up to 120 km without optical amplification or regeneration stages are considered in the experiment and the maximum reach whilst fulfilling current end user radio standard specifications is evaluated. 2. Experimental Setup The full duplex optical transmission path is shown in Fig. 1. Combination of fully-standard UWB (ECMA-368), WiMAX (802.16) and LTE (3GPP) signals was achieved using a RF power combiner (MiniCircuits ZN4PD1-50). These resulting composite signals were then applied to Mach-Zehnder modulators (MZM: Covega LN-058) working at the quadrature bias point for each 1300 nm and 1550 nm path. As shown, polarization and optical attenuation control was added prior to the MZMs to facilitate signal optimization. CW lasers, each launching 14.5 dBm (Applied Optoelectronics Inc. DFB-1310-BF-31-CW-FC-537 and Fitel FOL15DCWD -A81-19270-B), provided the 1300 nm and 1550 nm paths consecutively. The variable optical attenuators allow emulation of the optical launch power level used by operators defined as P Launch . Both paths were then combined using CWDM splitters (LAS-10- 086), providing 40 dB channel isolation. Standard single mode fiber (SSMF) was used as the transmission medium throughout the experiment. Signal detection was accomplished using 10 GHz bandwidth photodiodes (Discovery DSC-R402AC) followed by 56 dB RF amplification in both paths. UWB signal generation was provided by fully-WiMedia compliant Wisair WUSB dongles using time frequency code TFC6 (center frequency at 3.96 GHz with 528 MHz bandwidth), and dual-carrier modulation (DCM) [3] (at 480 Mbit/s). The UWB signals were analyzed by a Tektronix DPO 71254 oscilloscope. An Agilent EXA N9010A signal analyzer and two E4438C vector signal generators (VSG) provided signal analysis and generation for the LTE and WiMAX signals. The first VSG generated a fixed IEEE 802.16 WiMAX signal at 3.5 GHz using 16QAM½ (half-rate coding) in 24 MHz bandwidth [4] (41.75 Mbit/s). An advanced LTE signal was generated by the second unit using frequency division duplex at 2.6 GHz with full-complement 16QAM in 20 MHz bandwidth [5] (67.2 Mbit/s). Fig. 2(a) shows the electrical spectrum of the combined signals (RF in ). A 1.178 Gbit/s (2 x 589Mbit/s) aggregate data rate was achieved in the full-duplex transmission. DS 1550 nm RF in (DS) RF out (DS) SSMF L CWDM Splitter 1550 nm 1300 nm RF Amp EVM VOA CWDM Splitter 1550 nm 1300 nm CW Laser 1300 nm VOA CW Laser RF in (US) PIN RF out (US) RF Amp EVM PIN US DS US P Launch(1550 nm) P Launch(1300 nm) Fig. 1: Bi-directional CWDM experimental setup. CW: Continuous wave, DS: Downstream, US: Upstream, VOA: Variable optical attenuator OWB3.pdf OSA/OFC/NFOEC 2011 OWB3.pdf