Welcome to Gigabit-Wireless.com!

Welcome to Gigabit-Wireless.com

Welcome – to the informational site for Gigabit Wireless Networking.  We consider the available technologies for Gigabit Wireless Metropolitan Area Networks including:

Welcome to Gigabit-Wireless.com
Welcome to Gigabit-Wireless.com

Feel welcome to read our site and find out more about building modern, reliable and scalable Gigabit Wireless Networks for Wireless Metropolitan Area Networks (Wi-Man), 4G/LTE backhaul networks, Small Cell Backhaul, Corporate Networks and Campus and CCTV wireless networks.

We include technology introduction papers as well as usage cases to guide users in the very latest in Gigabit Wireless technology and deployment.  Modern wireless products can reach 10Gbps or higher capacity.

Applications for Wireless

Welcome - Gigabit Wireless
Gigabit Wireless Technology

Gigabit Wireless networks are used in a wide range of applications which include

  • Safe Cities
  • Smart Cities
  • 4G/LTE Backhaul Networks
  • Broadband Wireless
  • Last Mile Networks
  • Campus Sites
  • Corporate Networks
  • Education networks
  • Metro WiFi
  • Security and CCTV

If you are considering a wireless network with 10Gbps or higher capacity, please ask our team of experts who will be delighted to assist:

For further Information on 10GBE Wireless

For more information please Contact Us

 

What is DDM and DOM used in Optical SFP/SFP+ Transceivers?

What is DDM (Digital Diagnostic Monitoring)?

DDM or Digital Diagnostic Monitoring is a management technology which allows operators to monitor several parameters of a fibre optic transceiver, such as optical input/output levels, temperature, laser bias current and supply voltage. All of these parameters can be monitored in real-time.

Examples of optical modules supporting DDM are the Small Form Factor Pluggable modules such as SFP and SFP+ for 1Gbps to 10Gbps and up to 25Gbps capacity

SFP / SFP+ Optical Module with DDM / DOM Monitoring features
SFP module with DDM / DOM Feature

What does the DDM do exactly?

DDM is capable of providing component monitoring on transceiver applications in great detail. The system that is used is an extension of the interface defined in GBIC specification (GBIC being a type of transceiver).

The interface itself is capable of generating alarms and warning flags which alert the host system when operating parameters fall outside of a set of ‘normal operating’ rules. This allows the end user to isolate faults and predict failure.

What is DOM?

DOM or Digital Optical Monitoring is used to monitor certain parameters of an optical transceiver in real-time. This helps operators to identify the location of a fiber link failure which in turn helps to simplify the maintenance process and improve overall system reliability.

DOM gives you the ability to monitor the transmit and receive power of the optical transceiver module, its temperature and supply voltage. Each system can be configured to monitor transceivers that are in operation either globally or by specific port.

With DOM console message and syslog messages are sent if operation falls below or rise above the specific transceivers manufacturer thresholds.

Most modern transceivers support DOM functions.

Schematic diagram of Optical SFP/SFP+ module with DDM / DOM features
Schematic diagram of Optical SFP/SFP+ module with DDM / DOM features available on the (0) (1) and (2) pins

For More Information

Please Contact Us

Wi-Fi: 802.11 Physical Layer Explained

Find out more about the 802.11 Wi-Fi Physical Layer

This helpful poster created by Tektronix (R) explains key parameters in the WiFi Physical layer, including 802.11b, 802.11a, 802.11g, 802.11n, 802.11ac.

CableFree WiFi Physical Layer explained: find out about Wi-Fi!
WiFi Physical Layer Explained

A download link to the document in PDF format is here:

What Wi-Fi Parameters do we have to consider?

When building a Wireless Network Key parameters include:

  • Channel Allocation
  • Spectral Shape and Mask
  • Packet Information
  • Data rates
  • Modulation types
  • Transmitter Measurements
  • Channel and Centre Frequency

What is Wi-Fi 6? Wi-Fi 5? Wi-Fi 4?

Under its naming convention, the WiFi alliance calls 802.11ax Wi-Fi 6. 802.11ac is now WiFi 5, and 802.11n is WiFi 4. The idea, according to the WiFi Alliance, is to make matching endpoint and router capabilities a simpler matter for the rank-and-file user of WiFi technology.

Meanwhile it’s important to know that the Wi-Fi Alliance has not made up simpler names for all the 802.11 standards, so it’s important to be familiar with the traditional designations. Also, the IEEE, which continues to work on newer versions of 802.11, has not adopted these new names, so trying to track down details about them using the new names will make the task more complicated.

802.11b

Released in September 1999, it’s most likely that your first home router was 802.11b, which operates in the 2.4GHz frequency and provides a data rate up to 11 Mbps. Interestingly, 802.11a products hit the market before 802.11a, which was approved at the same time but didn’t hit the market until later.

802.11a

The first following the June 1997 approval of the 802.11 standard, this standard provided operation in the 5GHz frequency, with data rates up to 54Mbps. Counterintuitively, 802.11a came out later than 802.11b, causing some confusion in the marketplace because customers expected that the standard with the “b” at the end would be backward compatible with the one with the “a” at the end.

802.11g

Approved in June 2003, 802.11g is the successor to 802.11b, able to achieve up to 54Mbps rates in the 2.4GHz band, matching 802.11a speed but within the lower frequency range.

802.11n (WiFi 4)

The first WiFi standard to specify MIMO, 802.11n was approved in October 2009 and allows for usage in two frequencies – 2.4GHz and 5GHz, with speeds up to 600Mbps. When you hear the term “dual-band”, it refers to being able to deliver data across these two frequencies.

802.11ac (WiFi 5)

802.1ac-compliant devices operate in the 5 GHz frequency space. With Multiple Input, Multiple Output (MIMO) – multiple antennas on sending and receiving devices to reduce error and boost speed – this standard supports data rates up to 3.46Gbps. Some router vendors include technologies that support the 2.4GHz frequency via 802.11n, providing support for older client devices that may have 802.11b/g/n radios, but also providing additional bandwidth for improved data rates.

802.11ax (Wi-Fi 6)

Also called High Efficiency WLAN, 802.11ax aims to improve the performance in WLAN deployments in dense scenarios, such as sports stadiums and airports, while still operating in the 2.4GHz and 5GHz spectrum. The group is targeting at least a 4X improvement in throughput compared to 802.11n and 802.11ac., through more efficient spectrum utilization.

For Further Information

Please Contact Us

The rise of 60GHz V-Band Technology

60GHz V-Band Wireless Technology

60GHz (V-Band) is now becoming a popular frequency band in wireless world, with both short-range and wider area applications ahead for the tiny beams of this unlicensed millimeter radio technology.

60GHz V-Band Wireless

The frequency — part of the V-Band frequencies — is considered among the millimeter radio (mmWave) bands. Millimeter wave radios operate using frequencies from 30GHz to 300GHz. Until recently, 60GHz has typically been used for military communications as well as some commercial applications.

Major technology vendors show growing interest in the technology and the associated patents. Qualcomm Inc. (Nasdaq: QCOM) bought Wilocity recently to combine 60GHz WiGig technology with WiFi. Google (Nasdaq: GOOG) bought Alpental, a startup that, according to one of its founders, is using 60GHz to develop a “hyper scalable mmWave networking solution for dense urban nextGen 5G & WiFi.”

Why 60GHz, and why now? Here are a few reasons the market is expanding:

Drivers

WiGig:

A short-range wireless specification — using the Institute of Electrical and Electronics Engineers Inc. (IEEE) 802.11ad specification — that can link devices at up to 7 Gbit/s over a distance of up to 12 meters. That’s 10 times faster than the current 802.11n WiFi, though with less range. This makes the technology ideal for wirelessly delivering high-definition video in the home. The Wi-Fi Alliance is expecting WiGig-certified products to arrive in 2015. (See Wi-Fi Alliance, WiGig Align to Make WiFi Super Fast.)

Wireless backhaul:

Particularly for small cells, operators can use the 60GHz radios to connect small cells to a fiber hub. (See More Startups Target Small-Cell Backhaul.)

Wireless bridges:

These are useful for providing extra capacity at events, ad-hoc networks, and private high-speed enterprise links. (See Pushing 60.)

Wireless video: Some startups have jumped the gun on the WiGig standard and plowed ahead with their own 60GHz video connectivity using the Sony-backed WirelessHD standard.

Why 60GHz?

A global unlicensed band exists at 57-64GHz. It is largely uncongested compared to the 2.5GHz and 5GHz public bands currently used for WiFi. (See FCC to Enable Fast Streaming With New 60GHz Rules.)

There’s also a lot of it. “The 60 GHz band boasts a wide spectrum of up to 9GHz that is typically divided into channels of roughly 2GHz each,” Intel Corp. (Nasdaq: INTC)’s LL Yang wrote in an article on the prospects for the wide-area and short-range use of the technology. Spectrum availability is “unmatched” by any of the lower-frequency bands.

The spectrum is now open and approved for use across much of the world. This includes the US, Europe, and much of Asia, including China.

As we’ve already seen, 60GHz technology is expected to offer blazing wireless transmission speeds.

Issues with 60GHz

No technology is ever perfect, right?

Transmissions at 60GHz have less range for a given transmit power than 5GHz WiFi, because of path loss as the electromagnetic wave moves through the air, and 60GHz transmissions can struggle to penetrate walls. There is also a substantial RF oxygen absorption peak in the 60GHz band, which gets more pronounced at ranges beyond 100 meters, as Agilent notes in a paper on the technology. Using a high-gain adaptive antenna array can help make up for some of these issues with using 60GHz for wider area applications.

Some vendors have also argued that there are potential advantages for the technology over omnidirectional systems. “The combined effects of O2 absorption and narrow beam spread result in high security, high frequency re-use, and low interference for 60GHz links,” one vendor notes

For Further Information

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Gigabit Wireless MMW Radios Deployed in London

Corporate LAN connections in London using CableFree E-band MMW Radios

CableFree 1Gbps E-band MMW radios have been deployed for corporate customers above the busy streets of London as a high speed and cost-effective alternative to Fibre Optic Leased Lines.

CableFree E-Band MMW Link Installed in London
CableFree E-Band MMW Link Installed in London in 2018

The links carry full-speed LAN traffic for a major customer as an alternative to Fibre Optics.

Major Benefits of Wireless 1Gbps MMW Links

Compared to Leased Lines and Fibre Optics, wireless E-band links offer many benefits including:

  • Immediate availability: no waiting for digging, trenches or wayleaves
  • Fast to install: typically 3 hours to complete
  • One-off cost for asset purchase: No ongoing lease for service
  • Low-cost “Light License” at only GBP 50 per year (USD 75 in USA) protects “first use” of spectrum
  • Designed & Proven to be highly reliable in all conditions
  • Portable Asset: can be moved to other sites when needed
  • No disruption to link caused by digging or 3rd party maintenance work
  • Easy to maintain: just one box either end of link, fully manageable

Free Link Design and Consultancy Service

Our team offer a Free Link Design service direct from ourselves – the vendor – to verify reliable operation before purchase and deployment.  Based on 22 years experience of Broadband Fixed Wireless equipment design and installation, the experience of our Wireless team is unparalleled.

Available and Shipping

CableFree E-Band MMW Links are available today with up to 10Gbps per radio aggregating to 40Gbps full duplex capacity.

For Further Information

Please Contact Us

Upgrade your Lightpointe FSO Free Space Optic Laser Link

How to Upgrade your Lightpointe FSO Laser Link

Upgrade your Lightpointe Aire X-Stream FSO
Lightpointe Aire X-Stream FSO: time for upgrade?

Why upgrade your Lightpointe FSO link?

Lightpointe have announced by partners by email that they are discontinuing their entire range of FSO links.   This strategic move by Lightpointe away from FSO (Free Space Optical) technology means many FSO users will have to look for alternatives.
Many users own FSO links including Lightpointe  which are old and sometimes problematic.  Often, users require higher reliability, uptime, capacity or distance than their older FSO laser links can provide.

The Need for Reliability and High Availability

Modern IP networks demand higher capacity and uptime, and as FSO links are installed outdoors often in harsh conditions where they age faster than indoor mounted IT equipment such as switches and routers, which are installed in nice airconditioned environments.   Modern Carrier Class wireless equipment is designed for all-outdoor use including harsh environments and can ensure ultra-high availability and reliability in practical use.

Alternatives to Lightpointe and FSO

There are many alternatives available including Carrier Class FSO from other vendors, MMW links with 10Gbps+ capacity, Microwave links and MIMO radio.  These have different characteristics, capabilities and price points.  Modern links can offer up to 40Gbps capacity and for low-end solutions, MIMO radios at lower price points than FSO for sites where budgets are tight.

If the customer requires a direct replacement FSO link, there are relatively few FSO vendors currently available with reliable shipping products.

Other FSO vendors currently offering carrier grade FSO:

Lightpointe – FSO Laser Links – Free Space Optic laser links – Manufacturer information

Established in 1998, Lightpointe  provides optical communications at the speed of light which operate license-free. With products capable of sending up to 1 Gbps full duplex of data, Lightpointe offers reliable, fibre-optic connections without the need for expensive physical fibre.

Lightpointe – Manufacturer information

  • Lightpointe (based in USA) is a Manufacturer of FSO bridges
  • Built for line of site (LOS) with ranges suitable up to 2km
  • Ultra secure connections using narrow beams of light are secure from RF packet sniffers
  • Reliable availability with five nines availability
  • Licence free operation using FSO technology

Upgrading from Lightpointe AireBridge LX Quad Beam Laser Link

Lightpointe state that AireBridge LX models are the most advanced laser bridges in the industry, backed by patented technology refined over 5 product generations. For customers wanting the absolute longest range and highest availability, the LX is the answer. Your data will fly between buildings on 8 beams of overlapping invisible laser light, all transmitting simultaneously (4 transmission beams and 4 receiving beams at each side of the link).

  • Quad Beam
  • Tracking
  • Autopower
  • 250 Mbps full duplex
  • RJ45, PoE
  • Recommended for distances up to 1600 meters

Upgrading from Lightpointe AireBridge SX Single Beam, Wireless Bridge

Lightpointe state that the LightPointe AireBridge SX Single Beam, Wireless Bridge offers highly competitive pricing and extreme value for distances up to 750 meters. Utilizing an advanced single laser and “Avalanche Photo Diode” (APD), these bridges transmit and receive data simultaneously for full duplex connectivity. Each side of the link can be ordered in a 250 Mbps, 500 Mbps, or 1,000 Mbps configuration and can be upgraded later via software keys.

  • AireBridge System
  • Single Beam 250 Mbps full duplex
  • PoE Power
  • Recommended for 200 – 600 meters

Upgrading from a Lightpointe AireLite G (500m) Laser Link

Lightpointe state that the AireLite G is the latest addition to the LightPointe Optical Wireless product line and the new flagship of LightPointe’s high capacity single-beam, point-to-point Optical Wireless solutions, delivering real full-duplex Gigabit Ethernet throughput at a system latency of less than 50 microseconds. Additionally, the AireLite G offers several advanced features such as PoE operation, a web-browser-based and SNMP management, an integrated multiport Layer 2 switch fabric with multiple fiber and copper based network interface options, an integrated built-in alignment telescope, and an automatic lens defroster, just to mention a few. All features are designed within a compact, lightweight, fully outdoor rated and energy efficient package.

  • High Speed Connection Real full-duplex Gigabit Ethernet throughput.
  • Ultra Low Latency Fiber-like system latency (typically less than 50 microseconds)
  • Operating Distance Recommended operational distance up to 500 meters
  • Secure Operation Highest level of physical transmission security due to narrow angle transmission beam.

Upgrade Geodesy Gigabit Wireless FSO Free Space Optic Laser Link
Gigabit Wireless Technologies

Disclaimer

The technical specifications listed above are those advertised by the manufacturer.  No warranty is made to the accuracy of this information, which may vary widely in practical installations.  Many vendors are known to exaggerate or mis-state the capability of the equipment which they offer.

For More Information on Wireless Upgrades

If you would like more information on upgrading a Lightpointe FSO wireless solutions please Contact Us and our experienced team of wireless experts will be delighted to assist.

Upgrade your Geodesy FSO Free Space Optic Laser Link

How to Upgrade your Geodesy FSO Laser Link

Upgrade Geodesy FSO Free Space Optic Laser Link
Upgrade Geodesy FSO Free Space Optic Laser Link

Why upgrade your Geodesy FSO link?

Many users own FSO links including Geodesy / LaserBit which are old and sometimes problematic.  Often, users require higher reliability, uptime, capacity or distance than their older FSO laser links can provide.

The Need for Reliability and High Availability

Modern IP networks demand higher capacity and uptime, and as FSO links are installed outdoors often in harsh conditions where they age faster than indoor mounted IT equipment such as switches and routers, which are installed in nice airconditioned environments.   Modern Carrier Class wireless equipment is designed for all-outdoor use including harsh environments and can ensure ultra-high availability and reliability in practical use.

Alternatives to Geodesy and FSO

There are many alternatives available including Carrier Class FSO from other vendors, MMW links with 10Gbps+ capacity, Microwave links and MIMO radio.  These have different characteristics, capabilities and price points.  Modern links can offer up to 40Gbps capacity and for low-end solutions, MIMO radios at lower price points than FSO for sites where budgets are tight.

If the customer requires a direct replacement FSO link, there are relatively few FSO vendors currently available with reliable shipping products.

Other FSO vendors currently offering carrier grade FSO:

Geodesy – LaserBit – FSO Laser Links – Free Space Optic laser links – Manufacturer information

Established in 1996, Geodesy (formerly LaserBit) provides optical communications at the speed of light which operate license-free. With products capable of sending up to 1 Gbps full duplex of data, GeoDesy offers reliable, fibre-optic connections without the need for expensive physical fibre.

GeoDesy – LaserBit – Manufacturer information

  • Geodesy (formerly LaserBit in Hungary) is a Manufacturer of FSO bridges with claimed over 20,000 lasers installed
  • Geodesy claim 15 years experience of building wireless bridges
  • Geodesy claim Risk free 100% satisfaction guarantee on all laser products
  • Affordable solutions costing from £2,995 installed
  • Built for line of site (LOS) with ranges suitable up to 5km
  • Ultra secure connections using narrow beams of light are secure from RF packet sniffers
  • Reliable availability with five nines availability
  • Licence free operation using FSO technology

Upgrading from GeoDesy FSO AT Series

Geodesy state that the Auto tracking series is a 8th generation series that maintains precise beam alignment, even when environmental factors cause movement to the device. The AT series is also the most recommended solution from the GeoDesy range.

  • Beam Tracking System
  • Gigabit Ethernet connectivity up to 2500m
  • Full duplex connectivity
  • Secure and error free data transmission
  • Built-in automatic failover
  • License free operation

Upgrading from GeoDesy FSO AF Series

Geodesy state that the AF series is a 5th generation build, offering laser transmission using a unique modulation technique that ensures error free data transfer over distances up to 1000 meters.

  • Point to point communications up to 1 Gbps
  • Wireless Ethernet range up to 1000m
  • Error free data transfer
  • Secure data transmission
  • Built-in automatic failover
  • 99.999% availability

Upgrading from a GeoDesy FSO PX Series

Geodesy state that the PX 5th generation series offers speeds from 100 Mbps to 1 Gbps and ranges of connectivity up to 5000 meters, and suited for installations to solid structured buildings on budget constrained projects.

  • Point to point communications up to 1 Gbps
  • Wireless Ethernet range up to 5000m
  • Full duplex connectivity
  • Secure data transmission
  • Built-in automatic failover
  • Licence free operation

Upgrade Geodesy Gigabit Wireless FSO Free Space Optic Laser Link
Gigabit Wireless Technologies

Disclaimer

The technical specifications listed above are those advertised by the manufacturer.  No warranty is made to the accuracy of this information, which may vary widely in practical installations.  Many vendors are known to exaggerate or mis-state the capability of the equipment which they offer.

For More Information on Wireless Upgrades

If you would like more information on upgrading a GeoDesy AT/AF/PX wireless solutions please Contact Us and our experienced team of wireless experts will be delighted to assist.

Gigabit Wireless Links using V-Band 60GHz Millimeter Wave MMW Technology

Gigabit Wireless Links using V-Band 60GHz Millimeter Wave MMW Technology

So-called “V-Band” refers to high frequency microwave signals in the Millimeter Wave radio bands which enable high capacity wireless communications.  The band is useful for moderate distances up to around 1km with clear “line of sight”, and for short-range mobile devices.  In many countries, V-band is “Unlicensed” (license free) which encourages widespread use.

What is 60GHz V-band technology?

The V band (“vee-band”) is a standard designation by the Institute of Electrical and Electronic Engineers (IEEE) for a band of frequencies in the microwave portion of the electromagnetic spectrum ranging from 40 to 75 gigahertz (GHz).The V band is not heavily used, except for millimeter wave radar research and other kinds of scientific research. It should not be confused with the 600–1000 MHz range of Band-V (band-five) of the UHF frequency range.

CableFree V-Band 60GHz MMW Link
CableFree V-Band 60GHz MMW Link with High Gain parabolic antenna

The V band is also used for high capacity terrestrial millimeter wave communications systems. In the United States, the Federal Communications Commission has allocated the frequency band from 57 to 71 GHz for unlicensed wireless systems. These systems are primarily used for high capacity, short distance (less than 1 mile) communications. In addition, frequencies at 70, 80, and 90 GHz have been allocated as “lightly licensed” bands for multi-gigabit wireless communications. All communications links in the V band require unobstructed line of sight between the transmit and receive point, and rain fade must be taken into account when performing link budget analysis.

Applications for 60GHz V-band

Very short range Wi-Fi

The Wi-Fi standard IEEE 802.11ad utilizes the 60 GHz (EHF microwave) spectrum with data transfer rates of up to 7 Gbit/s for very short ranges of up to 10 metres (33 ft).  Also the newer IEEE 802.11ay uses the same band.  Where 802.11ad uses a maximum of 2.16 GHz bandwidth, 802.11ay bonds four of those channels together for a maximum bandwidth of 8.64 GHz. MIMO is also added with a maximum of 4 streams. The link-rate per stream is 44Gbit/s, with four streams this goes up to 176Gbit/s. Higher order modulation is also added, probably up to 256-QAM.

Mobile backhaul

As mobile operators need more and more bandwidth, they are turning to new frequency bands to lower their wireless backhaul costs. Both license-exempt V band spectrum (57-71 GHz) and E band spectrum (71-76 GHz, 81-86 GHz and 92-95 GHz) have clear technological and economic advantages. The 27 GHz allocated in these bands allows multi-Gigabit per second capacities far exceeding the 6-38 GHz bandwidth-limited frequencies.

In the V band and E band spectrum, wireless systems can utilize the significantly larger allocated spectrum and channels to deliver multi-Gigabit data rates. This enables a simple, robust, and low cost modem and radio design. Thus, V-Band and E-Band, millimeter-wave wireless systems provide significant cost advantages over 6-38 GHz wireless systems – allowing scaling capacity to Gigabit capacities, without additional radio equipment and licensing fees.

Wireless broadband

Internet service providers are looking for ways to expand gigabit high-speed services to their customers. These can be achieved through fiber to the premises broadband network architecture, or a more affordable alternative using fixed wireless in the last mile in combination with the fiber networks in the middle mile in order to reduce the costs of trenching fiber optic cables to the users. In the United States, V band is unlicensed. This makes V band an appealing choice to be used as fixed wireless access for gigabit services to connect to homes and businesses.

Satellite constellations

As of March 2017, several US companies—Boeing, SpaceX, OneWeb, Telesat, O3b Networks and Theia Holdings—have each filed with the US regulatory authorities “plans to field constellations of V-band satellites in non-geosynchronous orbits to provide communications services,” an electromagnetic spectrum that had not previously been “heavily employed for commercial communications services.”

V-Band Regulations and Licensing

In many countries, V-band is “Unlicensed” (license free) which encourages widespread use.  A few countries retain 60GHz for licensed or defence applications.  The specific frequencies which are allowed to be used can vary between different countries.

For More Information on V-Band Millimeter Wave

For more information on V-Band MMW, Please Contact Us

What is the actual maximum throughput on Gigabit Ethernet?

Examining the usable bandwidth on a Gigabit Ethernet network

Examining how much throughput of actual throughput can be achieved on a Gigabit Ethernet based network and how much this increases by using Jumbo Frames.  Also covered is how that relates to throughput of a Wireless Link with Gigabit Ethernet interfaces.

Gigabit Ethernet Physical Layer

On a Fibre Optic Gigabit Ethernet Network (1000BaseSX, 1000BaseLX), the raw line rate is 1.25Gbps.  This raw data rate is chosen to include 8b10b Line Coding.  Line Coding is used to ensure “DC balance” of the data stream, remove long runs of consecutive 0’s and 1’s, which makes the physical transceivers easier to design, implement, and maximises performance of the fibre optic transceiver range capability.  When the 8b10b line coding is removed from the raw data stream by the Gigabit Ethernet chipset, this allows an uncoded payload of exactly 1.0Gbps.

On a copper based Gigabit Ethernet Network (1000BaseT),  transmission uses four lanes over all four cable pairs for simultaneous transmission in both directions through the use of echo cancellation with adaptive equalization and five-level pulse amplitude modulation (PAM-5). The symbol rate is identical to that of 100BASE-TX (125 megabaud).

Gigabit Ethernet Net Data rate

The theoretical maximum bandwidth on a Gigabit Ethernet network is defined by a node being able to send 1 000 000 000 bits each second (bits per second, bps, bp/s), that is one billion 1 or 0s every second. A Byte of data consists of 8 Bits, hence the net capacity of this Gigabit link is the capability to transfer 125 000 000 bytes per second (1000000000 / 8), also termed Bbps, Bytes/sec or Bytes/s.

Frames, Preamble, Interframe Gap

In a real-world network, not all of the 125000000 bytes/second can be used to send data as there are multiple layers of overhead. Data transferred over a Ethernet based network must be divided into “frames”. The size of these frames regulates the maximum number of bytes to send together. The maximum frame size for Ethernet has been 1518 byte for the last 25 years or more.

 

Each frame will cause some overhead, both inside the frame but less known also on the “outside”. Before each frame is sent there is certain combination of bits that must be transmitted, called the Preamble, which basically signals to the receiver that a frame is coming right behind it. The preamble is 8 bytes and is sent just before each and every frame.

When the main body of the frame (1518 byte) has been transferred the network devices want to send another one. Since we are not using the old CSMA/CD access method (used only for half duplex) the devices do not have to “sense the cable” to see if it is free – which would incur a time penalty, but the Ethernet standard defines that for full duplex transmissions there has to be a certain amount of idle bytes before next frame is sent onto the wire.

This is called the Interframe Gap and is 12 bytes long. So between all frames devices have to leave at least 12 bytes “empty” to give the receiver side the time needed to prepare for the next incoming frame.

This will mean that each frame actually uses:

12 empty bytes of Interframe Gap + 1518 bytes of frame data + 8 bytes of preamble = 1538

This makes that each frame actually consumes 1538 bytes of bandwidth and if we remember that there are  “time slots” for sending 125000000 bytes each second this will allow space for 81274 frames per second. (125000000 / 1538)

So on default Gigabit Ethernet we can transmit over 81000 full size frames each second. Since Gigabit Ethernet is always at running full duplex we can at the same time receive 81000 frames simultaneously.

Nore detail on the overhead for this: For each frame, we lose 12 + 8 bytes used for Interframe Gap and Preamble, which is considered the “outside” of the frame. Plus, there is some more overhead is going on:

Ethernet header, Frame Check Sequence

The first 14 byte of the frame will be used for the Ethernet header and the last 4 bytes will contain a checksum trying to detect transfer errors. This uses the CRC32 checksum algorithm and is called the Frame Check Sequence (FCS).

The Maximum Transmission Unit, MTU

This means that we lose a total of 18 bytes in overhead for the Ethernet header in the beginning and the checksum at the end. (The blue parts above are seen as something like a “frame” around the data carried inside.) The number of bytes left is called the Maximum Transmission Unit (MTU) and will be 1500 bytes on default Ethernet. MTU is the payload that could be carried inside an Ethernet frame, see picture above. It is a common misunderstanding that MTU is the frame size, but really is the data inside the frame only.

IP Header, TCP Header, Maximum Segment Size

Just behind the Ethernet header we will most likely find the IP header. If using ordinary IPv4 this header will be 20 bytes long. And behind the IP header we will also most likely find the TCP header, which have the same length of 20 bytes. The amount of data that could be transferred in each TCP segment is called the Maximum Segment Size (MSS) and is typically 1460 bytes.

So the Ethernet header and checksum plus the IP and TCP headers will together add 58 bytes to the overhead. Adding the Interframe Gap and the Preamble gives 20 more. So for each 1460 bytes of datasent we have a minimum of 78 extra bytes handling the transfer at different layers. All of these are very important, but does cause an overhead at the same time.

Efficiency using Standard Ethernet Frames

At the beginning of this article we noted the potential to send 125000000 bytes/second on Gigabit Ethernet. When each frame consumes 1538 byte of bandwidth that gave us 81274 frames/second (125000000 / 1538). If each frame carries a maximum of 1460 bytes of user data this means that we could transfer 118660598 data bytes per second (81274 frames x 1460 byte of data), i.e. around 118 MB/s.

This means that when using default Ethernet frame size of 1518 byte (MTU = 1500) we have an efficiency of around 94% (118660598 / 125000000), meaning that the other 6% is used for the protocols at various layer, which we could call overhead.

Efficiency using Jumbo Frames

If supported by the connected equipment – enabling so called Jumbo Frames on all equipment in the chain, we could have a potential increase in the actual bandwidth used for our data. Let us look at that now:

A commonly used MTU value for Jumbo Frames is 9000. First we have to add the overhead for Ethernet (14+4 bytes), Preamble (8 bytes) and Interframe Gap (12 bytes). This makes the frame consume 9038 bytes of bandwidth and from the total amount of 125000000 bytes available to send each second we will have a total of 13830 jumbo frames (125000000 / 9038). So a lot less frames than the 81000 normal sized frames, but we will be able to carry more data inside each of the frames and by that reduce the network overhead.

(There are also other types of overhead: including CPU time in hosts, processing work done at network interface cards, switches and routers, but in this article we will only look at the bandwidth usage.)

If we remove the overhead for Interframe Gap, Ethernet CRC, TCP, IP, Ethernet header and the Preamble we would end up with 8960 bytes of data inside each TCP segment. This means that the Maximum Segment Size, the MSS, is 8960 byte and is a lot larger than default 1460 byte. A MSS of 8960 multiplied with 13830 (number of frames) gives 123916800 bytes for user data.

This will give us a really great efficiency, of 99% (123916800 / 125000000). So by increasing the frame size we would have almost five percent more bandwidth available for data, compared to about 94% for default frame size.

Wireless Links with Gigabit Ethernet Interfaces

Note that for Wireless links such as Microwave, Radio, Millimeter Wave or Free Space Optics, the Airside Interface often uses different coding and modulation than the network side interface.  This difference is often due to limitations in the amount of RF spectrum available (for example, a 40MHz, 56MHz, 60MHz, 80MHz or even 112MHz channel) from the regulatory body and channel planning, the modulation used (for example, up to 256QAM or 1024QAM) which affects both transmit power and receiver sensitivity, aggregation features such as MIMO or XPIC, and especially for longer links, the corresponding Link Budget between the two ends which includes the Antenna Gain at both sides, plus any losses caused by transmission waveguides, connectors, plus atmospheric fade effects.  This airside interface may therefore impose a lower capacity for the “end to end” wireless link even if the network interfaces at each end are connected at 1Gbps Gigabit Ethernet rate.

Transparent Wireless Links

Note that only some wireless technologies such as Free Space Optics (FSO) are capable of fully transparent transmission using the exact same modulation used on Fibre Optic networks, so the full 1.25Gbps line rate, along with all packet structure is maintained exactly.  The advantages of transparent transmission is that throughput is easily predicted, and latency is the lowest possible as transmission is generally one bit at a time.

Conclusion

The default Gigabit Ethernet has a potential frame throughput of 81000 per second and therefore a high throughput for actual data (about 118 MB/s), giving efficiency of 94%, or 940Mbps.  For networking equipment where Jumbo Frames are supported, by increasing the MTU to 9000 can deliver even more data on the same bandwidth link, up to 123 MB/s, thanks to the decreased amount of overhead by utilising a lower number of frames. Jumbo Frames can therefore potentially offer 99% of the theoretical Gigabit Ethernet bandwidth to carry data, which means 990Mbps capacity.

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IEEE 802.11ay wireless technology: Next-gen 60GHz WiFi

A new standard for 60GHz Wi-Fi goes beyond 802.11ad wireless speed & range

A new standard for high speed multi-gigabit WiFi is emerging.  Though products based on the IEEE 802.11ad (WiGig) standard have really only begun rolling out, an effort to deliver an enhancement called IEEE 802.11ay that promises to deliver faster and longer range Wi-Fi networks is gaining steam.

The up-coming 802.11ay is as an enhancement of 802.11ad in the unlicensed 60 GHz millimeter wave band of spectrum, and should be a natural upgrade. The upgrade will offer significant speed and range improvements.

IEEE 802.11ay 60GHz networking
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Technical Summary

802.11ay is a type of WLAN in the IEEE 802.11 set of WLANs. It will have a frequency of 60 GHz, a transmission rate of 20–40 Gbit/s and an extended transmission distance of 300–500 meters. It has also been noted that it is likely to have mechanisms for channel bonding and MU-MIMO technologies. It is expected to be released in 2017. 802.11ay will not be a new type of WLAN in the IEEE 802.11 set, but will simply be an improvement on 802.11ad.

Where 802.11ad uses a maximum of 2.16 GHz bandwidth, 802.11ay bonds four of those channels together for a maximum bandwidth of 8.64 GHz. MIMO is also added with a maximum of 4 streams. The link-rate per stream is 44Gbit/s, with four streams this goes up to 176Gbit/s. Higher order modulation is also added, probably up to 256-QAM.   802.11ay applications could include replacement for Ethernet and other cables within offices or homes, and provide backhaul connectivity outside for service providers.

What is the difference between ad and ay?

The 802.11ad standard was published in 2012 and the technology gives devices access to the unlicensed and relatively unclogged 60 GHz millimeter wave spectrum band for multimedia streaming, VR headset connectivity, computer-to-monitor wireless links and other apps that don’t require more than say 30 or 40 feet of unimpeded space. It has been adopted by chipmakers as well as vendors of routers, access points and other devices. The Wi-Fi Alliance runs a WiGig certification program for vendors, and the early 11ad gear on the market most commonly supports data transfer rates of 4.6Gbps – way faster than 802.11n and 11ac, but more limited in range and unable to penetrate solid objects.

The backwards compatible 802.11ay amendment to 802.11ad is designed to boost speeds several-fold. That initially would amount to a transmission rate of 20 to 30Gbps and a range of 33 to 100 feet with 11ay-to-11ay device setups, but once channel bonding, MIMO and other capabilities are exploited, you could be getting closer to 200Gbps and reaching distances approaching 1,000 feet, according to industry players.

11ay, as the specs are being developed, “is really allowing for a wider range of products than you’d get with ad, which has one set of data rates that everyone supports… ay has a lot more parameters to play with in channel bonding, MIMO and features at the MAC level to allow a far greater range of performance and products” according to one chipset vendor.

Other up-coming Fast WiFi standards: 802.11ax

IEEE 802.11ay 60GHz networking
IEEE 802.11ay 60GHz networking

Users should not confuse 802.11ay with 802.11ax, which will work in the 2.5 and 5 GHz bands.  The lower frequency bands for 11ax will penetrate walls.  11ay will not.

What will 802.11ay be used for?

It remains to be seen how soon the high speeds of 11ay will really be needed for internal uses, as 802.11ac — including Wave 2 products — are already pretty robust. But experts say that if 11ad doesn’t quite do it for you given its distance limitations, “11ay will finally be the technology that would let you snip that Ethernet cord – you no longer have to run Ethernet cables to everyone’s desk… there’s enough wireless bandwidth in ay.”

Many are enthusiastic about 802.1ay’s potential as a fixed point-to-point or point-to-multipoint outdoor backhaul technology, especially in light of scaled back fiber rollout plans by providers like Google and Verizon in the face of extraordinary costs associated with such implementations. “I’m more bullish on using ad & ay for backhaul (instead of mesh) in the case of campus & city networks — provided that it has a useful range” according to one industry expert

But it’s possible that 802.11ay could find a role in internal mesh and backbone networks as well as for other uses such as providing connectivity to VR headsets, supporting server backups and handling cloud applications that require low latency. “I believe that eventually, there will be enterprise applications for this – but it’s probably a few years into the future, given that we will have 802.11ax fairly soon & because there’s still a lot of 5 GHz band available for that (and ac).

When will 802.11ay become reality?

The 802.11ay task group had its initial meeting in 2015 and the spec only hit the Draft 0.1 stage in January. Though it is expected to reach Draft 1.0 by July 2017, according to the IEEE task group. If that mark is hit, expect pre-standard 11ay products to start rolling out within a year of that time.

Who is behind 802.11ay?

The IEEE task force leading the 11ay work includes representatives from major equipment and chipsets vendors.  The group states its goal as this: “Task Group ay is expected to develop an amendment that defines standardized modifications to both the IEEE 802.11 physical layers (PHY) and the IEEE 802,11 medium access control layer (MAC) that enables at least one mode of operation capable of supporting a maximum throughput of at least 20 gigabits per second (measured at the MAC data service access point), while maintaining or improving the power efficiency per station. This amendment also defines operations for license-exempt bands above 45 GHz while ensuring backward compatibility and coexistence with legacy directional multi-gigabit stations (defined by IEEE 802.11ad-2012 amendment) operating in the same band.”

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IEEE 802.11ax: The new standard for Wi-Fi

The new standard 802.11ax for Wi-Fi goes beyond 802.11ac wireless

A new standard for high speed multi-gigabit WiFi is emerging.  Current WiFi products use chips based on the IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11 and IEEE 802.11ac standard have really only begun rolling out, an effort to deliver an enhancement called IEEE 802.11ax that promises to deliver faster and longer range Wi-Fi networks.

The up-coming 802.11ax is as an enhancement of 802.11ac in the unlicensed 2.4 and 5GHz bands of spectrum, and should be a natural upgrade. The upgrade will offer significant speed and range improvements.

IEEE 802.11ax Wireless Networking
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Technical Summary

IEEE 802.11 ax is a type of WLAN in the IEEE 802.11 set of types of WLANs. It is designed to improve overall spectral efficiency especially in dense deployment scenarios. It is still in a very early stage of development, but is predicted to have a top speed of around 10 Gb/s, it works in 2.4 and/or 5 GHz, in addition to MIMO and MU-MIMO it introduces OFDMA technique to improve spectral efficiency and also higher order 1024 QAM modulation support for better throughputs. Though the nominal data rate is just 37% higher comparing with 802.11ac, the new amendment will allow achieving 4X increase of user throughput thanks to more efficient spectrum usage. It is due to be publicly released in 2019.

Modulation and coding schemes for single spatial stream
MCS
index
Modulation
type
Coding
rate
Data rate (in Mb/s)
20 MHz channels 40 MHz channels 80 MHz channels 160 MHz channels
1600 ns GI 800 ns GI 1600 ns GI 800 ns GI 1600 ns GI 800 ns GI 1600 ns GI 800 ns GI
0 BPSK 1/2 4 4 8 9 17 18 34 36
1 QPSK 1/2 16 17 33 34 68 72 136 144
2 QPSK 3/4 24 26 49 52 102 108 204 216
3 16-QAM 1/2 33 34 65 69 136 144 272 282
4 16-QAM 3/4 49 52 98 103 204 216 408 432
5 64-QAM 2/3 65 69 130 138 272 288 544 576
6 64-QAM 3/4 73 77 146 155 306 324 613 649
7 64-QAM 5/6 81 86 163 172 340 360 681 721
8 256-QAM 3/4 98 103 195 207 408 432 817 865
9 256-QAM 5/6 108 115 217 229 453 480 907 961
10 1024-QAM 3/4 122 129 244 258 510 540 1021 1081
11 1024-QAM 5/6 135 143 271 287 567 600 1134 1201

Technical improvements

The 802.11ax amendment will bring several key improvements over 802.11ac. 802.11ax addresses frequency bands between 1 GHz and 6 GHz. Therefore, unlike 802.11ac, 802.11ax will also operate in the unlicensed 2.4 GHz band. To meet the goal of supporting dense 802.11 deployments the following features have been approved.

Other up-coming Fast WiFi standards: 802.11ay

IEEE 802.11ax Wireless Networking
IEEE 802.11ax Wireless Networking

Users should not confuse 802.11ax with 802.11ay, which will work in the 60GHz bands.  The lower frequency bands 1-6GHz for 11ax will penetrate walls.  11ay will not.

What will 802.11ax be used for?

802.11ax is an upgrade for existing 802.11a, 802.11b, 802.11g, 802.11n and 802.11ac networks, Many are enthusiastic about 802.1ax’s potential as a fixed point-to-point or point-to-multipoint outdoor backhaul technology, especially in light of scaled back fiber rollout plans by providers like Google and Verizon in the face of extraordinary costs associated with such implementations. Therefore 11ax will find applications outdoors as well as indoors.

Who is behind 802.11ax?

The IEEE task force leading the 11ax work includes representatives from major equipment and chipsets vendors.
In 2012 and 2013, IEEE 802.11 received various submissions in its Standing Committee (SC) Wireless Next Generation (WNG) looking at issues of IEEE 802.11ac and potential solutions for future WLANs.  Immediately after the publication of IEEE 802.11ac in March 2013, the IEEE 802.11 Working Group (WG) established Study Group (SG) High Efficiency WLAN (HEW)

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