Make your optic network easy, Glsun PON Monitoring System

News【Brocade Revenue Down, IP Networking Slumps】

    Brocade reported quarterly revenue down 4% year-over-year, to $523 million, reflecting declines in both its IP networking business and the traditional storage networking lines that make up the bulk of its sales.Results were down 9% sequentially, with non-GAAP diluted earnings per share of $0.22, flat year-over-year and down from $0.29 sequentially.IP networking product revenue was $132 million, down 9% year-over-year, below outlook range, primarily due to lower router sales, down 33%, partly offset by stronger Ethernet sales, up 9% year-over-year. Reduced service provider and US federal sales drove the decline. Sequentially, IP Networking product revenue decreased 2% primarily due to lower Ethernet switch sales. That sequential revenue decline was primarily due to lower sales to enterprise customers as both the service providers and US federal revenue grew sequentially.

The Key to Optical Network: Optical Switch Technology and Application

With the application of DWDM systems and the development of optical communication technology, optical networking has become the trend of network development. The realization of optical network technology depends on optical devices such as optical switches, erbium-doped fiber amplifiers (EDFA) and wavelength division multiplexer (WDM), and the improvement of optical technology. DWDM (Dense Wavelength Division Multiplexing) technology is the key factor promoting all optical network development, while optical network put great opportunity and challenge in front of equipment manufacturers and telecom operators.

Optical switch is the key in all-optical switching that can achieve routing switching, wavelength selection, OXC and self-healing protection in the all-optical layer. At present, optical switch main applications are:

OXC (optical cross connect). Composed of optical switches arrays, OXC can realize dynamic optical path management, optical network fault protection and flexible new business addition. OXC requires low insertion loss, low crosstalk, short switching time and non-blocking operation. Currently, MEMS technology is put into use.

Realizing network automatic protection switching by optical switch. When fiber breaks or transmission fails, optical switch, like 1x2 optical switch, can change the transmission path to achieve business protection.

Network monitoring by 1xN optical switch. At the optical fiber test points of distal end, 1xN optical switch connects several fibers with OTDR (optical time-domain reflectometer) so as to achieve monitoring of all fibers. Or use the network analyzer to achieve network on-line analysis.

Optical fiber communication device testing. When testing optical device, fiber cable and system product, optical switch is able to test several devices so that thus simplifies the test and increases the efficiency.

OADM. It is mainly used in circular MAN, to achieve a single wavelength and a plurality of wavelengths transmitted in the optical path up and down freely. Optical switch OADM can control any dynamic wavelength up and down by software to boost the flexibility of network configuration.

Conventional optical switching technology mainly uses two technologies: solid state waveguide and optomechanical. Because of high crosstalk and power loss, solid state waveguide is limited in a switches array, not suitable to expansion in a large-scale switch array. While optomechanical has low insert loss and crosstalk, it is also not suitable to large-scale switch array for its large equipment and ordinary expansibility. So far, a lot of new technologies have emerged, mainly including MEMS, Inkjet bubble optical switch, the liquid crystal optical switch, thermo-optic effect switch, acousto-optic switches, holographic switches and so on.

The following specifications are used to examine an optical switch: switching time, array size, insert loss, reliability, expansibility and so forth. The developments of different technologies vary with the different applications. The following is a summary on the major optical switches types and their applications.

MEMS (micro-electromechanical system) optical switches. MEMS is likely to be one of the mainstreams of the core optical switch devices, because it is less affected by the format, wavelength, protocols, modulation, polarization and optical signal transmission direction, but performs better than other types in loss and scalability, which is consistent with the trend of the future development of optical network. The principle is to switch the light route by static electricity or other controls driving the movable micro mirror rotate. In spite of complicated production process, MEMS used IC technology to achieve mass-produces and decrease the individual cost.

Magneto-optic switches. As technology developing fast and expanding its horizon to wider fields, magneto-optic switches emerge as the times require. Magneto-optic switches boast higher switching speed, better durability, higher reliability, low voltage drive, and fail-safe latching. The sophisticated micro-technique is a push to high-technology industry. The applications are promising in high-end science, such as aerospace, military, fire monitoring, oil field detection, medical science and so on. Thus, a manufacture’s strength is reflected in whether it masters the magneto-optic switch technology and is able to produce it.

PON. Optical switches are widely used in PON monitoring system to build up all optical networks nowadays. PON is necessary to fulfill FTTx. With zero natural environment influence like thunder and lightning, PON is the best choice to meet the need of present networking. PON is composed of OLT, ONU, ONT and ODN, while optical switches integrated in these devices play great role to transmit mass data and monitor the networking in case of fault and ensure signal transmission.

Multi-channel optical switches. Optical switches can be integrated into a module or an equipment as multi-channel optical switches featured wide wavelength range, low crosstalk, high stability, high reliability and modularized design. At present, there are 1x4, 1x8, 1x16, 4x4, 1xN, MxN and module-type multi-channel optical switches.

Micro optical switches. It is the fundamental and widely used optical component, including 1x1, 1x2, 2x2, 2x2, D1x2,D1x2B, D2x2, 2x2F and so on. Micro optical switch is famous for its high performance, low insertion loss and compact dimension. It is an ideal component for OADM, OXC, system monitoring and protection. With compact package, it can be easily integrated into a high density optical communication system.

With the popularization of optical networking concept, optical switch technology has become the key to the future all optical network. This article briefly introduces the optical switch technology and application to help understand what is in the optical networking.

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Bandwidth Upgrade Stimulate Next Generation PON Technology Evolution

Bandwidth Upgrade Stimulate Next Generation PON Technology Evolution

    Recently, along with the growing needs of life, a variety of network-based applications are emerging. 3D TV, high-definition TV, 4K TV and even 8K television, virtual reality, and high-quality video services bring unparalleled audio-visual experience, and are becoming more common. Additionally, mobile devices like smartphones and tablet computers enable a large increase in network access devices and connections. In order to cope with such strong demand, PON technology providing high-bandwidth is widely used.

10G PON: the Mainstream Applied Technology of FTTx

      1G PON technology including EPON and GPON provides about 20-50 Mbps bandwidth for the end users. However, such bandwidth cannot fully meet the large bandwidth demand of 4K TV. Thus, ITU-T put forward XG-PON1 technology which can provide 10 Gbps (four times as GPON’s) downstream bandwidth and 2.5 Gbps (two times as GPON’s) upstream bandwidth. IEEE also proposed 10G EPON standard lifting the downstream speed up to 10Gbps. It is significant to have the equivalent bandwidth in some application fields. Nowadays, the research for 10G PON technology has been completed, a series of industry standard has been set, and the specification has been released, like the 802.3av of 10 G EPON, and ITU-T G.987 and G.988 of 10G GPON. In support of these standards, 10G PON devices can be mass-produced.

     Thanks to the mature industry chain and excellent performance, 10G PON has become the mainstream technology. It is suitable for a variety of deployment scenarios, such as buildings, residential renovation, high-end home, small and medium company broadband access, and mobile backhaul. The very key is that 10G PON and 1G PON can perfectly co-exist by reusing ODN and appropriate deployment of wavelength, which means that carriers can more easily achieve the smooth evolution of network construction. For traditional carriers, it helps improve user experience, enhance user stickiness, and maintain competitive position; for new carriers, it offers an idea to boost competitiveness in differentiation and competition.

10G PON Application: Building and Residential Renovation

      This application makes full use of the bandwidth of 10G PON technology, and provides large user covering and access bandwidth up to 100M even to 1G. Moreover, by fully using the existing resources UTP cable, twisted pair, network, etc., it can achieve rapid deployment and service fulfillment, thereby reducing capital expenditures. 

10G PON Application: High-end Home, Enterprise and Campus Broadband Access

      10G PON is the best selection for the brand new allocation serving the high-end users. It provides 1G to 10G bandwidth access sufficient to support high-end home and business users that demand high-bandwidth applications such as high-speed internet access, cloud storage, ultra-high-definition video, and 3D / VR online gaming service. In such situation, 10G PON access helps to improve user satisfaction thus consolidate, and even increase revenue.

10G PON Application: Mobile Backhaul

        In the era of mobile Internet, mobile communication occupies an important share of the communications market. Therefore, it is very necessary to offer carriers with a flexible-access and low-cost mobile traffic bearer solutions that can support massive business. And the 10G PON that can be deployed in various indoor and outdoor scenes is exactly in line with this demand. Not only 10G PON and small cell are perfect match, but also the existing FTTX resources give great convenience to LTE small cell that requires high-density deployments.

NG-PON2: 10G PON in The Future

       The existing mainstream 10G PON can ensure most communication services, yet the demand for bandwidth will be increasing. Ultra high-definition video services including VR and 8K TV, and the new generation mobile communication technology including Pre5G and 5G requires a lot of communication bandwidth, and is likely to bring greater data traffic in the future. Early in 2009, FSAN began researching NG-PON2, the next generation PON networking technology. In 2012, FSAN chose TWDM-PON as the mainstream NG-PON2 technology while PtP WDM PON as supplement. And it is regarded as the milestone in the history of NG-PON2 technology development. By the end of 2015, FSAN has finalized G.989.1、G.989.1 Amd1, G.989.1 Amd2, and a number of technical recommendations. At the same time, IEEE is in full swing researching and developing NG-EPON technology as a next-generation evolution direction for 10G EPON technology.

      At present, NG-PON2 corresponding standard G.989 series is in the research stage. And numerous details involving technical indicators and management methods await further discussion and confirmation. What’s more, the immature chain also greatly limits the commercialization of NG-PON2. Manufacturer’s NG-PON2 product is still in the prototype stage. Some of the key components like standard package optical modules are still very lacking, resulting in much higher cost of NG-PON2 than XG-PON1. Therefore, it is expected that NG-PON2 will be put into scale applications possibly after 2020.

Brief Introduction of FTTH

FTTx has been regarded as the most promising broadband access method after DSL. Different from DSL, FTTx has higher operating frequency, larger capability, smaller attenuation, anti – EMI, stronger anti-electromagnetic pulse capability, and better confidentiality.

FTTx is composed of several access forms, like FTTP (Fiber To The Premise), FTTB (Fiber To The Building), FTTC (Fiber To The Curb), FTTN (Fiber To The Neighborhood), FTTZ(Fiber To The Zone), FTTO (Fiber To The Office), FTTH (Fiber To The Home), and so on.

FTTH Is the Best Choice of Fiber Directly to the Home

To many homes, FTTH is the best choice that can link fiber and ONU (optical network unit) directly with houses. In addition to FTTD (Fiber To The Desk), it is the access method closest to users. With the formal generalization of fiber broadband access, it should be explained that FTTH broadband access is not only referred to fiber to the home, but also comprised of FTTO, FTTD and FTTN.

Moreover, the access plan -- 100Mbps into zone or building, 1-10Mbps to home -- is achieved by fiber + twisted pairs. FTTx + LAN is shared among many homes, which may not ensure the wideband bandwidth and network speed, while FTTH enables single home to enjoy broadband exclusively.

FTTH Technical Standard

At present, ADSL2+ and FTTH supporting exclusive broadband have become the main stream of future development. As for FTTH technology, besides APON (ATMPON), there are two standards competing: GPON (GigabitPON) set by ITU/FSAN, and EPON (Ethernet) set by IEEE802.3ah.

Based on ITU-TG.984.x, GPON is an integrated access standard for the new generation of broadband passive optical, whose bandwidth is 1111Mbit/s. Despite the difficult technology, it boasts many advantages like wide bandwidth, high efficiency, large covering range, and rich user interface, which makes it ideal to realize business network moving into broadband.

FTTH Arrangement Plan

OLT is put at the end of ISP centre to control the connecting, managing and maintaining of channels. The longest distance between OLT and ONU can reach 10-20km. OLT has function to measure the logic distance between every ONU and OLT, so as to manage ONU to adjust the time to send signal, which assures the signals sent from different ONUs can be received and multiplexed at OLT. Bandwidth allocation enables OLT to allocate the bandwidth in accordance with ONU demand. Meanwhile, OLT equipment has multipoint hub feature, which means one OLT is linked with 32 ONUs (open end), and all ONUs under one OLT share and multiplex 1G bandwidth, that is, each OLT can provide maximum 1Gbps uplink and downlink bandwidth. POS (passive optical splitter), which connects OLT and ONU, is a passive optical equipment that: allocates the input (downlink) optical signals to multi output ports so that multi users can share one fiber and bandwidth; multiplexes a plurality of ONU optical signals into one fiber.

ONU Generally Has 1-32 MB Ports to Connect a Variety of Network Terminals

ONU is the device at the client end to access the end user or corridor switches. It uses one fiber to achieve time division multiplexing of the signals from multi ONUs into one OLT port by one POS. Due to the multipoint tree topology, the convergence device investment is less and the network level is clearer. Most ONU has a certain switch function whose uplink port is the PON port connected to OLT by POS, while downlink combines 1-32 RJ45 ports of MB to GB with different data equipment, like switches, broadband routers, PCs, IP phones, set-top boxes, and so on, which fulfills the multipoint rapid deployment.

Build Up Network at Home

Generally, the ONU connecting FTTH to user end provides at least 4 RJ45 MB ports. For families with wired LAN connection within four computers, it fulfills the need to share Internet access. In addition, users using dynamic IP FTTH network are able to add switches or extend wired and wireless networks according to the demand.

In fact, the current broadband router can perfectly support FTTH access solution. For a fixed IP only providing one Mbps RJ45 interface FTTH terminal, it can be extended through a broadband router or wireless router. When set, the user simply need to find ‘WAN port’ option in the WEB setting interface of the router, select ‘Static IP’ of the WAN port connection type, and then enter the IP address, subnet mask, gateway, and DNS address provided by your ISP in the following interface.

Besides, those who purchase broadband router or wireless router should pay attention to the following if they want to use it as switch or wireless AP in FTTH network: the twisted pair plug from the ONU device should be directly inserted in any router LAN interface; the default DHCP server function should be closed in the router's administration page; the IP address of the router and the dynamic IP ONU device should be set as the same network segment.

FTTH is called ‘the King’ in broadband age thanks to its capability to provide unlimited bandwidth, and it is the ultimate goal of broadband development. FTTH will sharply boost the network speed that it only takes several seconds to download a 500MB movie, 10 times faster than the present ADSL. Furthermore, with the cost of FTTH construction reduced, FTTH is now coming to ordinary people's life.

Brief Introduction of OM1,OM2,OM3,OM4 Optical Fiber

Multimode fibers are identified by the OM (“optical mode”) designation as outlined in the ISO/IEC 11801 standard.

OM1, for fiber with 200/500 MHz*km overfilled launch (OFL) bandwidth at 850/1300nm (typically 62.5/125um fiber)

OM2, for fiber with 500/500 MHz*km OFL bandwidth at 850/1300nm (typically 50/125um fiber)

OM3, for laser-optimized 50um fiber having 2000 MHz*km effective modal bandwidth (EMB, also known as laser bandwidth), designed for 10 Gb/s transmission.

OM4, for laser-optimized 50um fiber having 4700 MHz*km EMB bandwidth designed for 10 Gb/s, 40 Gb/s, and 100 Gb/s transmission.

Table 1: Bandwidth and maximum distance of various fibers in gigabit transmission:

Fiber mode	Bandwidth	Bandwidth	1Gbps distance		10Gbps distance		Fiber grade
	850nm	1300nm
	Mhz*km	Mhz*km
MM			@850nm	@1300nm	@850nm	@1300nm
Standard 62.5/125μm	200	500	275m	550m	33m	300m	OM1
Standard 50/125μm	400	800	500m	1000m	66m	450m	OM1
Standard 50/125/62.5μm	500	500	550m	550m	82m	300m	OM2
50/125μm-110	600	1200	750m	2000m	110m	850m	OM2+
50/125μm-150	700	500	750m	550m	150m	300m	OM2
50/125μm-300	1500	500	1000m	550m	300m	300m	OM3
50/125μm-550	3500	500	1000m	550m	550m	550m	N.A
SM			@1310m	@1550nm	1310/1383/1550nm
Standard 9/125μm			5000m		10000m-40000m

Table 2: Bandwidth and attenuation of various fibers

Fiber mode	Bandwidth (Mhzkm)			Attenuation (db/km)
	OFB Overfilled Bandwidth		EMB  Effective Modal Bandwidth
MM	@850nm	@1300nm	@850nm	@850nm	@1300nm
Standard 62.5/125μm	200	500	220	3.5	1
Standard 50/125μm	500	500	510	3.5	1.5
50/125μm-150	700	500	850	3.5	1.5
50/125μm-300	1500	500	2000	3.5	1.5
50/125μm-550	3500	500	4700	3	0.7
SM				@1310nm	@1550nm
Standard 9/125μm				0.3	0.4

With the cost decrease of Ethernet equipment and the increasing requirements of network applications, 10 Gigabit Ethernet is bound to be put into application. Fiber becomes the first choice to be used in 10 gigabit Ethernet due to its light weight, large capacity and transmission bandwidth. Although single mode fiber can be used in optical networking, the cost of optical transceiver is high since laser is the light source in gigabit Ethernet. VCSEL light source has been researched to use with 50/125 fiber, which would support 300 metres transmission at 850nm. Meanwhile, this application also can provide 900 metres transmission without increase the cost.

Shorter than 2000 metres, the standard 62.5/125μm multimode fiber can be used within OC-12(622Mb/s). Single mode fiber is the best choice in the rest cases. However, things have been changed since the advent of OM3 multimode fiber. Since OM3 fiber lengthens the distance of Gigabit and 10 Gigabit transmission system, 850nm wavelength window used with VCSEL will be the best selection that is highest cost-effective for arrangement of wire. When the link is more than 1000 metres, single mode fiber is still the sole choice. Single mode fiber fulfills 5 km transmission distance at 1310 wavelength in the gigabit system, while in 10 gigabit system, it can cover 10 km distance. When link is or shorter than 1000 metres, OM3 50μm multimode fiber can be used in gigabit system while single mode fiber should be used in 10 gigabit system. In addition, when link is less than 300 metres, OM3 multimode fiber is universal in both gigabit and 10 gigabit system.

GLsun Science and Tech Co.,Ltd specified in Opto-Mechanical Fiber Optical Switches manufacture since 2001. Our optical switches include 1X2, 2X2, D2X2, D2X2B, 2X2A, 2X2F, ect. Single mode, OM2, OM3 or OM4 fiber are available.