Over the years, a lot of research works have been carried out to study the GPON network structure and different type of FTTx model. Some of them are discussed below.

A.M.J. Koonen et al. (2006) reviewed Fiber-optic technologies which enable cost-effective delivery of broadband services to users in multiple-access network architectures [12]. He also described that the dynamic network reconfiguration can optimize system performance, in particular, for roaming traffic loads such as in fiber-wireless networks.

Yong-Hun Oh et al. (2007) have described a fully integrated burst-mode upstream transmitter chip for gigabit-class passive optical network applications and was implemented in 0.18µm CMOS technology [13]. In order to control consecutive burst data, the transmitter proposed to use a reset mechanism with TX_enable as a burst envelope signal. The feedback from the monitoring photodiode (MPD) is separated by two independent paths for temperature compensation. The chip tested with chip-on-board configuration shows an average power of 2dBm with extinction ratio of above 12dB under 1.25Gb/s burst mode operation. Based on the measurement, their work complied with the GPON ITU-T Recommendation G.984.2.

Ivica Cale et al. (2007) theoretically described that a new service like Television (IPTV) and Video on demand (VoD) over Internet together with High Speed Internet access (HSI) have demand for very high bandwidth to customers [14]. XDSL have some form which can satisfy bandwidth demand (VDSL2) but have restriction regarding distance. Probably only suitable solution for high bandwidth demand with a long reach is using optical cable to customers (FTTx). One of the ways they have discussed using some type of Passive Optical Network (PON). Gigabit PON (GPON) is the most often type used by European and US providers (in addition with APON and BPON) while providers in Asia predominantly use EPON/GePON. Mainly they focused on an overview of Gigabit PON and analyzes network architecture, transmission mechanisms and power budget in GPON systems.

Derek Nesset et al. (2008) have simulated GPON System with a 1300 nm semiconductor optical amplifier which was developed for extended reach GPON applications [15]. The high gain of 29dB has enabled a commercial GPON system to operate over 60 km and with 128-way split.

Attila Mitcsenkov et al. (2009) have addressed on broadband optical access network design minimizing deployment costs, taking operation issues into account, using detailed cost and network models of the above listed FTTx technologies that suit best to actual networks due to detailed cost metrics used instead of just minimizing fiber lengths [16]. They presented a heuristic solution that works fast even for large problem instances, providing results with a difference less than approximately 10-20% from the computed Integer Linear Programming (ILP) optimum for smaller cases where ILP could be used. Along with those algorithms they present case studies of real-life network and service requirement instances.

Faruk Selmanovic et al. (2010) has provided a relation between GPON and NG Network. They have tryed to show that Gigabit Passive Optical Networks are very economical, effective, and reliable solution for triple play service [17]. Also, they showed GPON as technical and economical sound solution for Next Generation Network. They present details about GPON applications such as: GPON ONU as Uplink, GPON as metro net, multi-user per one GPON ONU, GPON as FTTH/B, etc. They mention mechanisms that are used for implementing GPON applications such as: DBA algorithm (algorithm for control of upstream speed), GEM (inner transmit method), protection schemes, and control of download speed as additional feature that is not included in the default GPON settings. Briefly, they look at other elements of GPON such as aggregation switch; voice service: V.5.2, SIP and H.248. Economic aspect of projects and/or solutions in telecommunication networks is very important factor; GPON is no exception. So, they try to present both economical and technical aspects of GPON in relation to telecommunication network, and other similar solution that are currently available.

Claudio Rodrigues et al. (2011) have reviewed and compare the current gigabit passive optical networks (GPON) fibre to the home (FTTH) based solution, and discussed an evolution scenario to future next generation PONs (XGPONs) and wavelength division multiplexing PONs (WDM-PONs) from an operator point-of-view, i.e., taking into account standardization, wavelength planning, optical line terminal as well as optical network terminal equipment and transmission convergence layer [18]. They also compare a proposed architecture for the provision of quintuple play services over orthogonal frequency division multiplexing (OFDM) in several aspects such as equipment requirements, capacity to the end user and limitations.

Marcelo Alves Guimaraes et al. (2011) have proposed a new technique for transmitting E1 streams in a more efficient bandwidth allocation scheme, by fragmenting E1 signals without using circuit emulation techniques [19]. It is based on the combination of spatial and temporal switching, has been simulated in a hardware description language (HDL) platform and the results demonstrate the potential use of the technique in GPON equipment.

Mazin Al Noor et al. (2012) discussed about analoge and digital signal transmission utilizing GPON-CWDM based RoF over long distance [20]. Optical-wireless access technologies have been considered the most promising solution to achieve effective delivery of wireless and baseband signals. They increase the bandwidth and extend the transmission distance at a lower budget and environmentally friendly. The means to accomplish this aim is to simplify the design by GPON via radio over fibre (RoF), which is able to provide much higher total bandwidth at a longer connection distance. The integration of an 18 channel coarse wavelength division multiplexing (CWDM) in the GPON, allows the use of less expensive, un-cooled lasers, operating with reduced energy consumption. They demonstrate the deployment of a combined wireless system, 3.5GHz WiMAX, 2.6GHz LTE and baseband signals with a bit rate of 2.5Gbps downlink and 1.25Gbps uplink in GPON-CWDM via RoF technology. The signals are transmitted to the bidirectional splitter-32 for 160km bidirectional SMF length and from the splitter to WDM-DEMUX for 50km SMF length. The CDF and CFBG are utilized to increase signal transmissions distance. As a result, they achieve an extension of the transmission distance to 600km. Furthermore, the results indicate open eye diagrams, a clear RF and bandwidth spectrum and consultation diagram as well as low-energy consumption; Q- factor, SNR and OSNR have improved.

Andrej Chu et al. (2013) proposed a solution by using ant colony optimization to design GPON-FTTH networks with aggregating equipment [21]. With the huge demands for the provision of inexpensive and fast broadband services, GPON has been considered to be the most attractive solution for providing broadband access network. However, due to the consideration of many design factors such as the number, types, positions of network elements and routing information, the optical network planning process often exhibits several challenges from the optimization point of view. This problem is generally NP-hard and cannot be solved in polynomial time by any currently known algorithms. They presented an algorithm based on the Ant Colony Optimization (ACO) method with dedicated post processing. Given a geographical location of a Greenfield area, proposed solution minimizes the overall GPON network deployment cost by selecting the optimum type of aggregating equipment, routing information and cost-effective locations of network elements. In the result section, different network examples are provided to illustrate the effectiveness of the ACO approach for this type of problem.

Rastislav Roka et al. (2014) analysed possible exploitation for long reach passive optical networks [22]. For the expansion of networks based on optical transmission media, it is necessary to have a detailed knowledge of advanced implementations for passive optical systems used in the access network. This contribution shortly discusses possible scenarios of exploitation for hybrid passive optical networks. A main part is focused on characteristics of the GPON network simulation environment and on results from simulation experiments related to the Long Reach Passive Optical Network effective utilization for various higher layers.

M. Irfan Anis et al. (2015) simulated an evaluation of 2.5Gbps bi directional GPON based FTTH link using advanced modulation formats [23]. GPON is a promising solution for increasing bandwidth requirements of customers which supports triple play services and is being considered as a solution for mobile back haul network. It also enables the delivery of cloud services with a high interconnection speed. The performance of the proposed system was studied when a single wavelength and two wavelengths were used for triple-play services with different modulation schemes. They aimed to provide a comparison of the performance of different modulation formats for GPON based simulation of an actual architecture considering Q factor, BER, optical power and OSNR.

From the above discussion and literature review, we observed that there is no detail analysis regarding the convergence of E1 traffic with existing triple play considering some important parameters like power budget, sensitivity threshold, output signal spectrum and transmission wavelength. In this work, a quad play GPON architecture will be designed and developed to exploit the full potential of GPON and to extend its last mile quality of service.