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  • WDM Optical Networking Solutions

    COMPUFOX offers a number of  WDM Optical Networking solutions which allow transport associated with a mix of services up to 100 GbE over dark fiber and WDM networks providing for the whole set of probably the most demanding CWDM and DWDM network infrastructure needs. Because the physical fiber optic cabling is expensive to implement for every single service separately, its capacity expansion using a WDM is a necessity.

    WDM Architectures

    WDM architecture

     

    WDM (Wavelength Division Multiplexing) is a concept that describes combination of several streams of data/storage/video or voice on the same physical fiber optic cable by utilizing several wavelengths (or frequencies) of light with each frequency carrying a different sort of data. There's two types of WDM architectures: CWDM (Coarse Wavelength Division Multiplexing) and DWDM (Dense Wavelength Division Multiplexing). CWDM systems typically provide 18 wavelengths, separated by 20 nm, from 1470nm to 1610nm according to ITU-T standard G.694.2. However, for different applications, there are different ITU-T standard to define the specific wave range and channels. Compared to CWDM, DWDM is defined in terms of frequencies. Some DWDM network systems provide up to 96 wavelengths, typically without any more than 0.4 nm spacing, roughly over the C-band range of wavelengths.

    CWDM Technology

    CWDM is proved to be the initial access point for many organizations due to its lower cost. Each CWDM wavelength typically supports as much as 2.5 Gbps and could be expanded to 10 Gbps support. This transfer rates are sufficient to aid GbE, Fast Ethernet or 1/2/4/8/10G Fibre Channel, along with other protocols. The CWDM is limited to 16 wavelengths and is typically deployed at networks as much as 80 km since optical amplifiers can't be used due to the large spacing between channels.

    DWDM Technology

    DWDM is a technology allowing high throughput capacity over longer distances commonly ranging between 44-88 channels/wavelengths and transferring data rates up to 100 Gbps per wavelength. Each wavelength can transparently have a wide range of services. The channel spacing from the DWDM solutions is defined by the ITU standards and can range from 50 GHz and 100 GHz (the most widely used today) to 200 GHz. DWDM systems can provide up to 96 wavelengths (at 50 GHz) of mixed service types, and can transport to distances up to 3000 km by deploying optical amplifiers (e.g., DWDM EDFA) and dispersion compensators thus enhancing the fiber capacity with a factor of x100. Due to its more precise and stabilized lasers, the DWDM technology tends to be more expensive in the sub-10G rates, but is really a more appropriate solution and it is dominating for 10G service rates and above providing large capacity data transport and connectivity over long distances at affordable costs.

    Note: COMPUFOX WDM optical networking goods are designed to support both CWDM and DWDM technology by utilizing standards based pluggable  CWDM/DWDM Transceivers such as SFP, XFP and SFP. The technology used is carefully calculated per project and according to customer requirements of distance, capacity, attenuation and future needs.

    DWDM OVER CWDM NETWORK

    The main benefit of CWDM is the price of the optics that is typically 1 / 3 of the price of the equivalent DWDM optics. This difference in economic scale, the limited budget that lots of customers face, and typical initial requirements to not exceed 8 wavelengths, means that CWDM is a popular entry point for a lot of customers. With COMPUFOX WDM equipment, a customer can start with 8 CWDM wavelengths however grow by introducing DWDM wavelengths in to the mix, utilizing the existing fiber and maximizing roi. By utilizing CWDM and DWDM network systems or the mixture of thereof, carriers and enterprises are able to transport services as much as 100 Gbps of data.

    Typically CWDM solutions provide 8 wavelengths capability enabling the transport of 8 client interfaces over the same fiber. However, the relatively large separation between your CWDM wavelengths allows growth of the CWDM network with an additional 44 wavelengths with 100 GHz spacing utilizing DWDM technology, thus expanding the present infrastructure capability and making use of the same equipment included in the integrated solution.

    Fiberstore

    Additionally, the normal CWDM spectrum supports data transport rates as high as 4.25 Gbps, while DWDM is utilized more for large capacity data transport needs as high as 100 Gbps. By mapping DWDM channels inside the CWDM wavelength spectrum as demonstrated below, higher data transport capacity on the same fiber optic cable is possible without any requirement for changing the existing fiber infrastructure between the network sites. As demonstrated through the figure beside, CWDM occupies the following ITU channels: 1470 nm, 1490 nm, 1510 nm, 1530 nm, 1550 nm, 1570 nm, 1590 nm, and 1610 nm, each separated from the other by 20 nm. COMPUFOX can insert into the of the 4 CWDM wavelengths (1530 nm,1550 nm,1570 nm and 1590 nm), a set of additional 8 wavelength of DWDM separated from one another by only 0.1 nm. By doing so up to 4 times, the CWDM network capability can easily expand by up to 28 additional wavelengths.

    The other figure below further demonstrates in detail the expansion capabilities via the DWDM spectrum. As seen below, just one outgoing and incoming wavelength of the existing CWDM infrastructure can be used for 8 DWDM channels multiplexing in to the original wavelength. Since this DWDM over CWDM network solution is integrating the DWDM transponders, DWDM MUX/DeMUX and EDFA (optical amplifier if needed), the entire solution is delivered simply by adding a really compact 1U unit. This expansion is achieved with no service interruption to the remaining network services, or to the data, and with no need to change or replace any of the working CWDM infrastructures.

    Fiberstore

    Advantages of COMPUFOX WDM Optical Networking Solutions

    COMPUFOX CWDM and DWDM network equipment provides the following advantages:
     
    Low-cost initial setup with targeted future growth path.
    Easy conversion and upgrade capabilities up to 44 wavelengths
    Easy upgrade to support 10G, 40G and 100G services
    Seamless, non traffic effective network upgrades
    Reliable, secure, and standards based architecture
    Easy to install and maintain
    Full performance monitoring
     

    With COMPUFOX compact CWDM solutions, you could get all of the above benefits and much more (such as remote monitoring and setup, integrated amplifiers, protection capabilities, and integration with 3rd party networking devices, etc.) inside a cost effective 1U unit, enabling you to expand as you grow, and utilize your financial as well as physical resources towards the maximum.

    To purchase your CWDM and DWDM transceivers, please click on the links below:

     

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  • Huawei Completes 5G Key Technology Tests in the Field Trial Sponsored by IMT-2020 5G Promotion Group

    [Shenzhen, China, May 27, 2016] Huawei completed the first phase of key 5G technology tests as a part of a series field trials defined by the IMT-2020 5G Promotion Group. In April 2016, the outdoor macro-cell tests, conducted in Chendu, China, consist of a number of the foundational key enabling technologies and an integrated 5G air-interface. The test results successfully demonstrated that the new 5G air interface technology can effectively improve spectrum efficiency and to meet diverse service requirements for 5G defined by ITU-R.


    Huawei completes 5G key technology tests in 5G field trial

    Strong Promotion for Global Partnership on 5G Technology Innovation and a Global 5G Standard

    Launched by China Academy of Information and Communication Technology (CAICT), the IMT-2020 5G Promotion Group aims to foster a joint effort to promote 5G technology evaluation and field test among the global mobile industry and ecosystem to ensure the successful commercial deployment by 2020. One of the key objectives for IMT-2020 5G Promotion Group is to realize the 5G vision for the enhanced mobile broadband service as well as to create the new capabilities for 5G to enable the IoT and vertical services, this represents the unprecedented technical challenges such as to realize 10Gbps or peak rate 20Gbps user data rate, 100 billion connections, and 1 ms of end-to-end network latency for the 5G air interface.

    Early this year, IMT-2020 5G Promotion Group announced a three phase 5G networks trial plan, spanning from 2016 to 2018, with a first phase test from September 2015 to September 2016. The first phase test is focused on key radio technologies and performance test.

    As one of the core members in the IMT-2020 5G Promotion Group, Huawei actively contributed IMT-2020 5G Promotion Group and 5G technology test. In addition, Huawei established an extensive collaboration with CAICT, China Mobile, China Unicom, and China Telecom in the Chinese operator community to explore the innovative air-interface technologies to achieve best spectral efficiency and massive links capabilities. Huawei’s effort is focused on New Radio (NR) technology, which includes the optimized new air-interface, full-duplex and massive MIMO technologies, these are the enabling technologies to achieve the superior end-user experience for the emerging mobile broadband service such as 4K, 8K and virtual reality and augmented reality.

    Best-in-Class Test Results Using 5G New Air Interface

    The 5G air interface technology has been implemented through three novel foundational technologies, i.e., filtered Orthogonal Frequency Division Multiplexing (F-OFDM), Sparse Code Multiple Access (SCMA) and Polar code to meet 5G requirements and performance targets.

    F-OFDM technology is the basis for creating ultra-flexible air-interface to adaptively fit all the 5G use-case scenarios defined by ITU-R with a single radio technology platform. It allows multiple concurrent radio numerologies and frame structure to deliver very diverse services; F-OFDM can ensure the future-proof for the 5G system to meet emerging innovative services requirements. The test results showed that F-OFDM can increase system throughput by 10% using those free guard bands in LTE system. In addition, F-OFDM supports asynchronous transmission from different users. Test results showed that it will provide 100% higher system throughput compared with that in LTE system in the presence of mixed service on the same carrier frequency with mixed radio numerologies. .

    SCMA is to support massive connections and obtain higher system throughput simultaneously via the joint optimization on sparse SCMA codebook design and multi-dimensional modulation. It can further consider optimization on power allocation among different SCMA layers especially in downlink to improve total system throughput. The test results showed that SCMA is to increase the uplink connection number by 300% and at the same time increased the downlink system throughput up to 80%.

    For Polar code, it allocates information to the highly reliable data locations in the code structure to transmit useful information of user and at the same time it supports channel coding of any code rate with an appropriate code construction to fit any future service requirements. The test results showed that Polar code provided coding gain from 0.5dB to 2.0dB compared with Turbo code used in LTE system.

    System Integration of Innovative 5G Air Interface Technologies

    The flexible system integration of several innovative 5G air-interface technologies, namely, F-OFDM, SCMA and massive MIMO has been verified in the first phase of key 5G technology tests. In the test, multi-user MIMO (MU-MIMO) supported up to 24 users and up to 24 parallel layers transmission on the same time-frequency resources. The test results showed that MU-MIMO can achieve 3.6Gbps cell average throughput using 100MHz system bandwidth, it is almost 10 times of that in LTE baseline system.

    The trial has validated the optimal integration of the above new radio technologies and the capability of flexible 5G air-interface technologies, the trial is also served as a technical re-risk to support the on-going 3GPP standardization work.

    Full Duplex Implemented in the First Phase of 5G Test

    Full Duplex mode has also been tested in the first phase of 5G test. In the initial test stage on Full Duplex, it allows simultaneous transmitting and receiving of data at the base station with three level cascaded technologies, namely, passive analog cancellation, active analog cancellation, and digital cancellation. The test results showed that the Full Duplex can provide self-interference cancellation capability more than 113dB in real world environment and result in a total 90% system throughput gain over the conventional half duplex mode used today.

    Huawei has successfully completed the first phase test of 5G technologies in China. "The trial of 5G technologies in China will be a great contribution to 5G applications in the future.” Dr. Wen Tong, Huawei 5G Chief Scientist emphasized that, "As a member of the IMT-2020 5G Promotion Group, Huawei is pleased to work with CAICT, China Mobile, China Unicom, and China Telecom, and took the initiative to be the first to complete 5G key technologies tests and corresponding system integration test based on our proposed 5G new air interface."

    He also announced the plan of the second phase of 5G test which will focus mainly on the wide coverage, high hotspot capacity, and massive connections with high reliability, low latency with reduced power consumption.

    Read more »
  • Ethernet Passive Optical Network Tutorial

    EPON is a PON-based network that carries data traffic encapsulated in Ethernet frames. Unlike other PON technologies which are based on the ATM standard, it uses a standard 8b/10b line coding and operates at standard Ethernet speed. This lets you utilize the economies-of-scale of Ethernet, and provides simple, easy-to-manage connectivity to Ethernet-based, IP equipment, both at the customer premises and at the central office.

    EPON Network Structure

    A typical EPON system is composed of OLT, ONU, and ODN (Figure 1).

    EPON Network Structure
    Figure 1. EPON Network Structure

    The OLT(Optical Line Terminal)resides in the Central Office (CO) and connects the optical network to the metropolitan-area network or wide-area network, also known as the backbone or long-haul network. OLT is both a switch or router and a multi-service platform which provides EPON-oriented optical interfaces. Besides the network assembling and access functions, OLT could also perform bandwidth assignments, network security and management configurations according to the customers’ different QoS/SLA requirements.

    The ONU(Optical Network Unit)is located either at the end-user location or at the curb and provides optical interfaces which are connected to the OLT and service interfaces at users’ side such as voice, data and video.

    The ODN(Optical Distributed Network)is an optical distribution network and is mainly composed of one or more passive optical splitters which connects the OLT and ONU. Its function is to split downstream signal from one fiber into several fibers and combine optical upstream signals from multiple fibers into one. Optical splitter is a simple device which needs no power and could work in an all-weather environment. The typical splitters have a splitting ratio of 2, 4, 8, 16 or 32 and be connected to each other. The longest distance the ODN could cover is 20 km.

    EPON Downlink and Uplink Technology

    In an EPON the process of transmitting data downstream from the OLT to multiple ONUs is fundamentally different from transmitting data upstream from multiple ONUs to the OLT.

    In the downstream direction, Ethernet frames transmitted by the OLT pass through a 1:N passive splitter and reach each ONU. N is typically between 4 and 64. This behavior is similar to a shared-medium network. Because Ethernet is broadcast by nature, in the downstream direction (from network to user), it fits perfectly with the Ethernet PON architecture: packets are broadcast by the OLT and extracted by their destination ONU based on the media-access control (MAC) address (Figure 2).

    Downstream Traffic in EPON
    Figure 2. Downstream Traffic in EPON

    In the upstream direction, due to the directional properties of a passive optical combiner, data frames from any ONU will only reach the OLT, and not other ONUs. In that sense, in the upstream direction, the behavior of EPON is similar to that of a point-to-point architecture. However, unlike in a true point-to-point network, in EPON data frames from different ONUs transmitted simultaneously still may collide. Thus, in the upstream direction (from users to 13 network) the ONUs need to employ some arbitration mechanism to avoid data collisions and fairly share the fiber-channel capacity (Figure 3).

    Upstream Traffic in EPON
    Figure 3. Upstream Traffic in EPON

    EPON and ADSL Comparison

    The requirement of bandwidth is increasing crazily with the incoming of digital age. Therefore the current high speed copper cable ADSL (Asymmetric Digital Subscriber Line) cannot meet our needs longer. The bandwidth of ADSL is limited to only a few megabit per second and the upstream and downstream bandwidth are not equal either. However, optical fiber has larger bandwidth and superior transmission capability which reaches gigabit per second. Hence, optical fiber used in access network is the future trend. And since Ethernet is low cost, uncomplicated widely-used in current network, and its application is very popular nowadays. So it is not hard to see that it is feasible and economical to combine them together. EPON technology combines a mature Ethernet technology and high-bandwidth PON technology, which is an ideal access method to achieve integrated services. In the future, highbandwidth business will surely drive up existing EPON which has the rate of 1.25Gbps in both the downstream and upstream directions.

    EPON Technical Advantages

    EPONs are simpler, more efficient, and less expensive than alternate multiservice access solutions. Key advantages of EPONs include the following:

    Higher bandwidth: up to 1.25 Gbps symmetric Ethernet bandwidthLower costs: lower up-front capital equipment and ongoing operational costsMore revenue: broad range of flexible service offerings means higher revenues

     

    With the growing of EPON technology, interaction standards and EPON devices, EPON has entered the large scale application phase driven by the huge market demands. EPON is fit for the access market which is at the end of the fibers and which has a certain density and these markets include FTTH, FTTP, FTTB, FTTN etc.

    EPON becomes a very economical and effective broadband access solution because of its predominance in equipment investment and also the operations, maintenance and etc. It could be said that the EPON technology has become the developing direction of access network’s technologies in the future as an ideal solution for FTTH.

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  • COMPUFOX SFP+ Direct Attach Copper Cables Solution

    Overview
    SFP+ Direct Attach Copper Cable, also known as Twinax Cable, is an SFP+ cable assembly used in rack connections between servers and switches. It consists of a high speed copper cable and two SFP+ copper modules. The SFP+ copper modules allow hardware manufactures to achieve high port density, configurability and utilization at a very low cost and reduced power budget.

    Direct Attach Cable assemblies are a high speed, cost-effective alternative to fiber optic cables in 10Gb Ethernet, 8Gb Fibre Channel and InfiniBand applications. They are suitable for short distances, making them ideal for highly cost-effective networking connectivity within a rack and between adjacent racks. They enable hardware OEMs and data center operators to achieve high port density and configurability at a low cost and reduced power requirement.

    Compufox SFP+ copper cable assemblies meet the industry MSA for signal integrity performance. The cables are hot-removable and hot-insertable: You can remove and replace them without powering off the switch or disrupting switch functions. A cable comprises a low-voltage cable assembly that connects directly into two SFP+ ports, one at each end of the cable. The cables use high-performance integrated duplex serial data links for bidirectional communication and are designed for data rates of up to 10 Gbps.

    Types of SFP+ Direct Attach Copper Cables

    SFP+ Direct Attach Copper Cable assemblies generally have two types which are Passive and Active versions.

    SFP+ Passive Copper Cable
    SFP+ passive copper cable assemblies offer high-speed connectivity between active equipment with SFP+ ports. The passive assemblies are compatible with hubs, switches, routers, servers, and network interface cards (NICs) from leading electronics manufacturers like Cisco, Juniper, etc.
     
    SFP+ Active Copper Cable
    SFP+ active copper cable assemblies contain low power circuitry in the connector to boost the signal and are driven from the port without additional power requirements. The active version provides a low cost alternative to optical transceivers, and are generally used for end of row or middle of row data center architectures for interconnect distances of up to 15 meters.

     

    Applications of SFP+ Direct Attach Copper Cables

    -Networking – servers, routers and hubs
    -Enterprise storage
    -Telecommunication equipment
    -Network Interface Cards (NICs)
    -10Gb Ethernet and Gigabit Ethernet (IEEE802.3ae)
    -Fibre Channel over Ethernet: 1, 2, 4 and 8G
    -InfiniBand standard SDR (2.5Gbps), DDR (5Gbps), and QDR (10Gbps)
    -Serial data transmission
    -High capacity I/O in Storage Area Networks, Network Attached Storage, and Storage Servers
    -Switched fabric I/O such as ultra high bandwidth switches and routers
    -Data center cabling infrastructure
    -High density connections between networking equipment

     

    Compufox SFP+ Direct Attach Copper Cables Solution

    Compufox SFP+ twinax copper cables are avaliable with custom version and brand compatible version. All of them are 100% compatible with major brands like Cisco, HP, Juniper, Enterasys, Extreme, H3C and so on. If you want to order high quality compatible SFP+ cables and get worldwide delivery, we are your best choice.

    For instance, our compatible Cisco SFP+ Copper Twinax direct-attach cables are suitable for very short distances and offer a cost-effective way to connect within racks and across adjacent racks. We can provide both passive Twinax cables in lengths of 1, 3 and 5 meters, and active Twinax cables in lengths of 7 and 10 meters. (Tips: The lengths can be customized up to the customers' requirements.)

    Features
    -1m/3m/5m/7m/10m/12m available
    -RoHS Compatible
    -Enhanced EMI suppression
    -Low power consumption
    -Compatible to SFP+ MSA
    -Hot-pluggable SFP 20PIN footprint
    -Parallel pair cable
    -24AWG through 30AWG cable available
    -Data rates backward compatible to 1Gbps
    -Support serial multi-gigabit data rates up to 10Gbps
    -Support for 1x, 2x, 4x and 8x Fibre Channel data rates
    -Low cost alternative to fiber optic cable assemblies
    -Pull-to-release retractable pin latch
    -I/O Connector designed for high speed differential signal applications
    -Temperature Range: 0-70°C
    -Passive and Active assemblies available (Active Version: Low Power Consumption: < 0.5W Power Supply: +3.3V)

     

    FAQ of Compufox SFP+ Direct Attach Copper Cables

    Q: What are the performance requirements for the cable assembly?
    A: Our SFP+ copper passive and active cable assemblies meet the signal integrity requirements defined by the industry MSA SFF-8431. We can custom engineer cable assemblies to meet the requirements of a customer’s specific system architecture.

    Q: Are passive or active cable assemblies required?
    A: Passive cables have no signal amplification in the assembly and rely on host system Electronic Dispersion Compensation (EDC) for signal amplification/equalization. Active cable assemblies have signal amplification and equalization built into the assembly. Active cable assemblies are typically used in host systems that do not employ EDC. This solution can be a cost savings to the customer.

    Q: What wire gauge is required?
    A: We offer SFP+ cable assemblies in wire gauges to support customers' specific cable routing requirements. Smaller wire gauges results in reduced weight, improved airflow and a more flexible cable for ease of routing.

    Q: What cable lengths are required?
    A: Cable length and wire gauge are related to the performance characteristics of the cable assembly. Longer cable lengths require heavier wire gauge, while shorter cable lengths can utilize a smaller gauge cable.

    For all you SFP+ Direct attach cables, please see link below. We carry compatible cables for most major brands.

    http://www.compufox.com/SFP_Cables_s/337.htm

        

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  • Verizon, CWA, IBEW reach tentative deal to end strike of wireline workers

    By Sean Buckley  FierceTelecom.com

    Verizon and the Communications Workers of America (CWA) and International Brotherhood of Electrical Workers (IBEW) have come to a tentative agreement on a four-year labor contract, putting an end to a month long strike of the telco's nearly 40,000 wireline workers.

    U.S. Secretary of Labor Thomas Perez announced the agreement in a statement issued on the agency's website Friday morning.

    "Today, I am pleased to announce that the parties have reached an agreement in principle on a four-year contract, resolving the open issues in the ongoing labor dispute between Verizon's workers, unions, and management," Perez said in a statement. "The parties are now working to reduce the agreement to writing, after which the proposal will be submitted to CWA and IBEW union members for ratification."

    Perez said that "I expect that workers will be back on the job next week."

    Verizon offered the wireline unions a nearly 11 percent raise, a small increase in pension benefits, and a promise to add 1,400 new union jobs. In addition, Verizon agreed to scale back subcontracting and withdrew a proposal to relocate employees for extended periods -- two issues that were sticking points for the unions and the company. 

    Marc Reed, Verizon's chief administrative officer, said in a statement that "Verizon is very pleased with this "agreement in principle." 

    The tentative contract was praised by both leaders of the IBEW and CWA. Both unions said that they will share the contract details with their members for approval in the coming days.

    "This tentative contract is an important step forward in helping to end this six-week strike and keeping good Verizon jobs in America," said Lonnie Stephenson, IBEW President, in a statement.

    Chris Shelton, President of the CWA, echoed a similar sentiment.

    "The agreement in principle at Verizon is a victory for working families across the country and an affirmation of the power of working people," Shelton said.

    On May 16, Perez met with Lowell McAdam, chairman and CEO of Verizon; Chris Shelton, president of the Communications Workers of America; and Lonnie Stephenson, president of the International Brotherhood of Electrical Workers.

    During that joint meeting, the three parties said they agreed to find a way to resolve their disputes and return to the bargaining table on Tuesday to continue talks.

    After not being able to negotiate what the CWA and IBEW deemed a fair contract with Verizon, the company's wireline workers began their strike on April 13. 

    At that time, neither the unions nor the company were able to come to an agreement over various issues related to health care, pension, and outsourcing job functions.

     

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