GPON as a Solution of Bandwidth Sharing for Triple Play with High Performance and Low Cost

Transcription

1 GPON as a Solution of Bandwidth Sharing for Triple Play with High Performance and Low Cost Md. Hayder Ali 1 and Md. Saiful Islam 2 Data growth in telecom market has reduced the prominence of traditional wire line broadband technologies such as digital subscriber line and cable modem. These technologies are not efficient enough to meet the customers demand for high-bandwidth applications such as high speed internet access, video-on-demand, high definition TV, IPTV and online gaming. In this scenario, fiber-to-the-home (FTTH) technology, which offers advantages like high bandwidth capacity and the delivery of high speed, high quality and multi-play services (data, voice and video) through a single channel, presents a strong business opportunity for telecom operators. Gigabit Passive Optical Networks (GPON) is a burning technology in the world. Full Service Support, including voice (TDM), Ethernet, ATM, leased lines, and others. Strong Operations, Administration, Maintenance, and Provisioning (OAM&P) capabilities offering end-to-end service management. GPON not only provides substantially higher efficiency as a transport network, but also delivers simplicity and superb scalability for future expansion in supporting additional services. GPON technology is cheaper than typical Ethernet Network. Sometimes it (GPON) saves more than seven to Eight times cost then Ethernet. This paper makes a technical and economical comparison between GPON and Ethernet technology and shows the results of threshold analysis between GPON and EP2P. Keywords: LDP (Local Distribution Point), BDB (Building Distribution Box), OLT (Optical Line Terminal), ONU (Optical Network Unit), ONT (Optical Network Terminal), ODF (Optical Distribution Frame). Introduction Fiber to the x (FTTx) is a generic term for any broadband network architecture using optical fiber to replace all or part of the usual metal local loop used for lastmiletelecommunications. Fiber to the x (FTTx) is a collective term for various optical fiber delivery topologies that are categorized according to where the fiber terminates. Fiber access is one of the most important technologies in the next generation network. It increases the access layer bandwidth and builds a sustainabledevelopment access layer network. OAN (Optical Access Network) adopts technologies: active point-to-point (P2P) Ethernet and passive optical network (PON). Figure-1: FTTx Structure 1,2 Bangladesh University of Engineering and Technology (BUET), 1 hayder.iict@gmail.com, 2 mdsaifulislam@iict.buet.ac.bd

2 In this figure-1 shows that if Splitted fiber directly goes to client Node/Premises/ Home then client will enjoy the device dedicatedly and if splitted fiber goes to Building s basement then from ONU/ONT client will enjoy their connectivity by short UTP cable. We analyze the main characteristics and requirements of the users and we simulate the behavior of the GPON technology using the OPNET Modeller software. This paper provides an economic and technical study comparing both solutions. The results allow choosing the technology that is more reliable, simple and cheaper to support voice IP, Internet and high definition television. If we consider 50 Mbps per user as bandwidth objective [4], we only are going to simulate the behavior of GPON networks since they are shared networks and the results must indicate the boundary in terms of bandwidth and number of users with EP2P. Anyway simulation it s not necessary in unshared networks as EP2P with enough bandwidth per user. This paper is organized as follows: Section 2 GPON Technology. How GPON Technology works is described in section 3. In section 4 the cost comparison is presented. GPON simulation is described at section 5 while results of simulation is described at section 6. Finally the conclusion and discussion is outlined in Section GPON Technology GPON or Gigabit Passive Optical Network is an optical technology based on the industry standard ITU-TG.984x which was ratified in This technology was originally developed to provide high speed Ethernet services for residential and small business customers. It supports higher rates, enhanced security, and choice of Layer 2 protocol (ATM, GEM, and Ethernet). A passive optical network (PON) is a pointto-multipoint, fiber to the premises network architecture in which unpowered optical splitters are used to enable a single optical fiber to serve multiple premises, typically A PON consists of an optical line terminal (OLT) at the service provider's central office and a number of optical network units (ONTs, ONUs) near end users. A PON reduces the amount of fiber and central office equipment required compared with point-to-point architectures. A passive optical network is a form of fiber-optic access network. 2.0 How GPON Technology works GPON has a downstream capacity of Gb/s and an upstream capacity of Gbp/s that is shared among users. Encryption is used to keep each user's data secured and private from other users. Although there are other technologies that could provide fiber to the home, passive optical networks (PONs) like GPON are generally considered the strongest candidate for widespread deployments. It provides unprecedented bandwidth (shared by up to 128 premises), and a greater distance from a central office (20 to 40 kilometers), allowing service providers to enable bandwidth-intensive applications and establish a long-term strategic position in the broadband market. In downstream GPON do broadcast to all of Connected ONT.

3 Figure-2: GPON Broadcasting Enterprise GPON is also a carrier class technology that provides a high level of Quality of Service (QOS) % for those customers with mission-critical requirements. GPON manufactures are now working on devises that will allow up to 10Gbs on bandwidth. In Upstream GPON use TDMA. Figure-3: GPON TDMA As a result, the a new standard known as G987 or also known at 10-PON has 10 Gbit/s downstream and 2.5 Gbit/s upstream framing is G-PON like and designed to coexist with GPON devices on the same network. This is great news for data network managers looking for low-cost, high-bandwidth, networking technologies in order to keep up with the demands on data applications and growth including cloud services. By GPON Technology service provider could provide several service to its customers like- IP TV, Voice (VoIP), Video, Data Connectivity, Internet connectivity, value added service ( Online gaming, Social networking, Video on Demand etc) and other services.

4 3.0 Cost Comparison The cost comparison between Ethernet Connectivity and GPON Connectivity is given bellow. From the bellow tables, it is clearly understand that GPON Connectivity is cheaper than the traditional Ethernet connectivity. An approximation is given bellow- Table-1: Ethernet Connectivity cost calculation (Approx.) Table-2: GPON Connectivity cost calculation (Approx.) FTTH Connectivity- Figure-4: FTTH Connectivity Structure Figure- 4: FTTH Connectivity Structure

5 Table-3: FTTH Cost Calculation FTTB Connectivity- Figure-5: FTTB Connectivity Structure Table-4: FTTH Cost Calculation 4.0 GPON Simulation We have done a simulation by OPNET OPNET proposes hierarchical structure of pattern for creating new simulation scenarios [1]. We have done the simulation separately in three parts. Like- A. OLT Design:

6 Figure-6: OLT Simulation in OPNET Reception: It has three modules. Receiver and Filter get incoming packets and identifying the ONU id that the packet sends. Report_Manager extracts the bandwidth allocation and saves this information. Transmission: This module only sends the generatedpackets for the node. The modules are Transmitter and Origin_Transmitter. Management: This is the most important module in thedesign. Manager realizes the calculation for establishing the bandwidth allocations for every ONU. [1]. B. ONU/ONT Design: We have design ONU/ONT in two part because of the simplification of simulation. I. ONU/ONT Upstream Design Firstly for upstream (figure 13) it has two sections: reception and transmission. Reception has three modules: Receiver: Get incoming packets from the link; Filter: Filter incoming packets owner; Entry_Manager: Extract upstream bandwidth info allocation from the packet received. Transmission has the next modules: Consumer: Create packet voice, packet data and packet video, for sending; Enduser_Traffic_Manager: Classify packet types, send packets and control upstream bandwidth allocation; Transmitter: Send packets to OLT.

7 Figure-7: ONU/ONT Upstream Simulation in OPNET II. ONU/ONT Downstream Design Secondly for downstream (figure 8) it has the same parts of upstream and the design is very similar. Figure-8: ONU/ONT Downstream Simulation in OPNET In this way, in the reception part, Entry_Manager disappears, because the traffic received comes in directly at User_Manager who distributes it to the Users modules. The transmission part has the next modules: User_Manager :It distributes incoming traffic to Users and note the new downstream bandwidth request; Users : It consumes downstream traffic; Transmitter : Send packets to OLT. 5.0 Results We present two tables for results. The first table shows the maximum bandwidth consumed for upstream and downstream for all scenarios simulated. For example, in the scenario with 32 ONU, the maximum bandwidth for downstream is Mbps, and for upstream is Mbps. If increase the number of ONU connected then

8 decrease the maximum bandwidthsupported in both ways. The maximum values supported for every scenario are in the figure 9. Figure-9: Maximum Bandwidth Supported by ONU/ONT. Figure-9 shows the number of supported user with respect to active ONU/ONT for 50 Mbps for every user. If we connect 100% ONU/ONT then the network supports 75 users with 50 Mbps for every user. For 50% active ONU/ONT, it supports 110 users. If decrease the percentage of Active ONU/ONT, increase the number of users. Figure-10: User Supported by 50 Mbps For technical evaluation we have took a commercial pack service. This pack has allowed having a point of reference for comparing both technologies. The pack has two options of services, both of them offers 50 Mbps for downstream and for upstream changes between 1 Mbps and 3 Mbps [10]. Bandwidth capacities for the different services included in Triple Play are: Voice IP uses 15Kbps with G.723 codec; Television IP requires 8Mbps for high definition channel and 1,5Mbps for standard channel and Internet access between 6Mbps and 10Mbps for downstream and 1Mbps for upstream. Once both technologies have been analyzed and compared the main conclusions are [13].

9 EP2P solution have the network architecture more simple than GPON, because haven t any device between central office and customers. The management of EP2P network is more easy that GPON, because dynamic bandwidth allocation is not necessary in EP2P. The costumers in GPON topology are restricted, because the functionalities and capacity network depends on the number of users connected. GPON has more exploitation of infrastructure than EP2P, because the optical fiber link is shared for the users. EP2P present more expansion capacity and have more bandwidth capacity than GPON. [1]. For GPON Operation and Maintenance is centralized. 6.0 Conclusion EP2P don t have bandwidth problems due network topology and optical fiber capacity, but that solution at this time is not adequate from economic point of view. According the simulations results, GPON technology supports 75 users to offer 50Mbps with 100% of actives ONU and it supports 208 users to offer 50Mbps with 25% of actives ONU. If we suppose that 25% is a percentage acceptable of active users so GPON is a good solution for networks topology fewer than 208 users and this value becomes the threshold between GPON and EP2P. With the same manner we can calculate the threshold between GPON and EP2P depending on the percentage of active users required. That consideration is very important in FTTB (GPON + VDSL) access networks due the number of users available usually. If only analyses economic environment the best solutions is GPON technology because it has CAPEX and OPEX fewer than EP2P. If only analyses technical environment the best solution is EP2P technology because offers more bandwidth and more scalability than GPON. Analyzing both environment, technical and economical, with the actual requirements and users, the best solutions is GPON depending on the user number, although if analyses futures requirements and potential users the best alternative is EP2P. Networks ability to deliver high bandwidth has made investments in this infrastructure very important for operators. They are increasingly deploying FTTH technology to complement their wireless networks. Spectrum crunch is another major factor that has led operators to look for viable alternative mediums. Also, to achieve the broadband targets set by the government under the National Telecom Policy, it will be important to drive FTTH growth along with other technologies. GPON, through the Generic Framing Procedure (GFP)-based adaptation method, offers a clear migration path for adding services onto the PON without disrupting existing equipment or altering the transport layer in any way. In conclusion it could conclude that GPON Connectivity is more efficient then Ethernet connectivity. It is possible to provide 7/8 GPON Connectivity by the cost of one Ethernet connectivity. References [1] Arie. Carrier Ethernet over GPON and EP2P. Omnitrons Systems Technology, Inc. 2008

10 [2] Cederic. Passive Optical Networks PRINCIPLES AND PRACTICE. Elsevier s Science & Technology Rights Department in Oxford, UK [3] Design of passive optical network. Department of telecommunications. Brno University of Technology. [4] Germán, José, Jordi. Analysis of the threshold between GPON and EP2P.UniversitatPolitècnica de Catalunya BarcelonaTech, (E-Print). [5] Germán, Jordi. Quality of Service in Multioperator GPON Access Networks with Triple Play Services. Transaccions on Engineering, Computing and Technology. Vol [6] ITU-T/G.984.1, Gigabit-Capable Passive Optical Networks (GPON): General Characteristics. [7] ITU-T/G.984.3, Gigabit-Capable Passive Optical Networks (GPON): Transmission Convergence Layer Specification. [8] IEEE 802.3ah. Ethernet in the First Mile Task Force, Point to Multipoint Ethernet on SM Fiber (PON). [9] ITU-T/G A Broadband Optical Access System with Increased Service Capability Using Dynamic Bandwidth Assignment. [10] Ivica, Aida, Matija, Gigabit Passive Optical Network-GPON. Conf. On Information Technology Interfaces [11] Ken. EP2P and GPON battle for hearts and minds. Telecommunications Online & Horizon House Publications [12] Keiser. FTTX concepts and applications. A John Wiley & Sons, Publication.,2006 [13] Lartigue. The Utility-Telco Promise-Capturing New Revenue Streams with GPON. Alcatel-Lucent. Vol 1, Issue [14] Simon. Open Access Network. FTTH Council Conference, India. 2011