WiFi Bridges: Point-to-Point & Point-to-Multipoint Links

Wifi Bridges are used for point-to-point links and point to multipoint links

Long-distance point to point links: Ubiquiti offers several types of bridges that are excellent options:

• The NanoBridge series is the best equipment for point-to-point links: One NanoBridge on each end of the link.
• For very long-distance links (over 7 miles): Use a Ubiquiti RocketM5 with a RocketDish on each side of the link:
• Use the 30dBi RocketDish (2-FT diameter) for less than 20 miles.
• For more than 20 miles, use the RocketDish 34dBi, which is 3-FT in diameter.

Point-to-point bridges: Antenna-type used in a is parabolic-type  antenna

• Parabolics are also known as "dish" or "grid" antennas. Grid or dish antennas are far better than Yagi for point to point.
• Ubiquiti bridges have a parabolic antenna integrated as part of the bridge

Point-to-multipoint bridges: Antenna-type is typically sectoral or panel antenna, but yagi antennas can be used.

• For long point-to-point to multipoint links to end-users (such as a marina): RocketM2 with a large 2.4GHz sectoral antenna
• For long point-to-multi-point links to locations such as a building: Use Ubiquiti RocketM5 with a large 5GHz sectoral antenna
• Point-to-multipoint bridge using Ubiquiti NanoSation M5 (5GHz) passing signal through 3 or 4 walls in an apartment building with NanoStation M5 on each end

WiFi Frequency Ranges: 2.4GHz, 5GHz, 900MHz: Uses, advantages & disadvantages of each frequency band

Mounts for Bridges

If you are not an expert, and you are experimenting with trying to make a very long-distance link, Try this:

• Use a signal booster with a high-gain antenna on one end: See the example network diagram. Test and, if there is not enough signal strength, put a high-gain antenna on both ends.
• If there is not enough signal strength, Put a high-gain grid antenna (such as the A24 Grid Antenna above left) on both ends.

Rocket M5 on a tripod mount

NanoBridge - an excellent low-cost bridge solution

right: snaps in the backside of dish / left: snaps in the backside of Ubiquiti antenna

Point to Point Links 7-15 miles with RocketM5 and RocketDishes

How not to do it: The images below with the air-conditioner in front of the RocketDish and the RocketDish in the middle of the roof, rather than at the edge, are how not to s your RocketDish! The RocketDish MUST be at the edge of the roof so that there is clear air under it for 10FT to 20FT.

air-conditioner blocking signal

Place the rocket on the edge of the roof (not like this)

right: snaps in the backside of the dish left: snaps in backside of Ubiquiti antenna

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SOLUTION:

1. Replace the 30dBi RocketDishes with the 34 dBi RocketDishes (3FT in diameter). This will give us 4 more dB and narrow the beam.
2. Fresnel zone: Seven-mile links need at least 50’ of clear air in the middle. We need to check the height of the towers at each end and see if any buildings are sticking into the Fresnel zone.
3. Have you enabled DFS Channels on that link? If not, replace the radios with US RocketM5s, enable DFS, and use 5500-5700…
4. You could switch it to 5840 RIGHT NOW and get more power. You have it on 5240 which is in the low band and restricted to 100mw. If you move it to 5840 (available on US), you can get 1,000mw…
5. We changed the encryption to from WEP to WPA2-AES because WEP hogs the CPU: We got an IMMEDIATE gain of 60Mbps (went from 180 to 240 immediately)

FOOTNOTES:

1. MCS is modulation and coding scheme. The target receive signal level to achieve a MCS 15 data rate of 144 Mbps is: -64 to -69 dBm. This level should also provide a 20 dBm SNR in very noisy areas. 2. This link passes through a city of about 400,000 people - but the path of the signal is not very densely populated: However, there is a federal border patrol facility where at least 100 agents are stationed right in the path, and we speculate that they are using much or most of the 5GHz spectrum. 3. Ubiquiti gear on each side of the link: RocketM5 with RocketDish 30dB parabolic antenna 4. F-64 dbm signal strength is the most optimum in any link. 5. When the RocketDish was set in the middle of the roof, with an air-conditioner too close to it and thus partially blocking the signal: We were troubleshooting of low data-rate issue with this link:

Analysis of the link: The Tx/Rx are only 180/180… Should be 250-300 each. Signal -62 is not a strong enough signal for MCS 15 [see footnote 1]. So, this link needs the larger 34 dBi RocketDishes rather than the 30dBi RocketDishes that we are using. 7 miles isn’t that far, unless the link passes through a congested area, as this one does (see footnote 2). In a rural or suburban area, we get 240mbps-270mbps over 10 miles with the 34dBi rocket dishes.

Optimizing Throughput on Point-to-Point Links w/Ubiquiti gear

Example of attempting to obtain 50Mbps throughput on point-to-point links:

• The actual throughput bit-rate is about half of the bitrate shown in Ubiquiti AirControl
• If the radio signal strength is showing very good (i.e., -64 dbm) but the throughput is much lower than your expectation, then the problem is interference.
• CCQ is the best benchmark for interference:
  • 98 - 100 CCQ is very good.
  • 50 - 70 CCQ is terrible and indicates a lot of re-transmissions
  • 71 to 97 is between good and bad
  • Falling CCQ is indication of increasing interference in an area.
  • CCQ is not the percentage of packets passing successfully to the other side of the link, but there is a correlation between a high CCQ and the percentage of packets passing through the link.
• Ubiquiti POE switches have a default throughput set at 10Mbps: Of course, this would be the limitation if you are using a Ubiquiti POE switch and have not changed this setting to 100Mbps.

Another Potential Solution: Wide Channel: Bond two channels with 20Mbps each, to make one Wide Channel with 40Mbps

• Wide Channel is not a configuration option in AirControl
• Wide Channel is more susceptible to interference

-64 dbm signal strength is the most optimum in any link

Longest distance link: 174KM with Ubiquiti Rockets & 34dBi dishes

• One of our customers created this 100-mile link from mountain peak to mountain peak. We believe this may be a record-breaking WiFi long-range link.
• It is a backbone link carrying data and VOIP traffic to/from a distant community. We saw the link in operation: Signal quality was above 90% consistently.

10 KM link using Bullet5's & 20dBi panel antennas

A customer comments that he made a 10km link using 2 Ubiquiti Bullet5 and 2 panel antennas A20N of 20dBi. This customer says it's perfectly working.

Point-to-point link 1/2 mile with line of sight

Ubiquiti LocoM5 is a 5GHZ AP with an integrated 13dBi panel antenna. The range is 3 to 5 km.

1/2 mile is very easy to bridge with low-cost gear. Parabolic antennas would be best, but you can easily make this link with panel antennas. If there are a lot of WiFi signals in the area, you should use 5GHz. For example, a Ubiquiti LOCO5 or LOCOM5 on both sides would make this link.

The LOCO5 or LOCOM5 on one side should be set up in bridge mode and on the other side in AP mode.

3-mile Point-To-Point Link with end-users on both sides: "How To"

SCENARIO from customer: We are in discussion with a group about a potential new site for our WiFi service. This site would consist of two access points that will use a WDS relay configuration. The two access points will be about three miles apart on different islands with no objects between them. There will be end users at both locations. If we get the go-ahead, what Ubiquiti equipment would you recommend we use for this installation?

OUR RESPONSE: For the point-to-point 3-mile link, I recommend the NanoBridge 5GHz 25dbi on both sides. To reach the end users at the two locations Depends on how close they are to the APs, and I will assume that they are using 2GHz. So so the APs each side, I recommend one LOCO2 or LOCOM2 on each side (if they are within 2KMs of the APs and there is no obstruction of line of sight) and if they are KMs away from the APs, then I would recommend one NS2 or NSM2 on each side.

Point-to-Point link: 8-miles

For this link, we recommend a Ubiquiti RocketDish 30dBi combined with RocketM5 at each end. The critical issue is the depth of the Fresnel zone: We will need the latitude and longitude of the two endpoints. The RocketDish 30 is 2 ft in diameter.

Below is the diagram from the customer:

Bridge 2KM for Video, VoIP, and data transmission

CUSTOMER QUESTION: I am looking at installing wireless communication, which will transmit Video, VoIP, and data.

A bit about the layout: Site "A" is the primary location, and Site "B" is the remote location (2 km apart with a line of sites). The two WiFis are to be bridged with the highest possible throughput. Remember that it must adhere to frequency legalities in Ontario, Canada.

I want the highest gain possible on a parabolic-type antenna and a good outdoor power AP.

RECOMMENDED SOLUTION from Data Alliance: Because the distance is only 2 km, you should use a NanoBridge 5GHz 22dBi for this application. One NanoBridge is needed on each end. The highest possible gain of a parabolic antenna would be 34dBi, but even using 25dBi would be overkill for this short distance. Canada and the USA have the same legal frequencies.

Use one NanoBridge 22dBi on each side of the link to easily bridge 2KM for voice, video, and data.

NanoBridge doubles throughput vs. NanoStation.

We replaced some point-to-point links that were using NSM5 by upgrading to NanoBridge M5 25dBi, and the throughput through the links doubled!

This is an example of how parabolic antennas (like that of NanoBridge), which are more directional than the panel antenna of NanoStation, eliminate signal noise and thereby significantly improve signal and throughput.

Backhaul Top 5: High Data Rate, High Throughput Point-to-Point Gear Mfgs.

Summary of 5 major players in the backhaul market along with the premium point-to-point solutions that they have to offer:

1. Redline Communications offers radio platforms operating between 3.5 and 38 GHz. These platforms support multiple inputs and outputs and enhanced radio technology to provide the industry's leading throughput.

The Technology:

One of the point-to-point solutions offered by Redline is the AN 80i. It uses enhanced IEEE 802.16 radio technology to deliver high data rate and high throughput along with the lowest latency in the industry. It works in the license-free 5 GHz band, and its radio platform can be configured to provide point-to-point and point-to-multipoint access between users and networks.

Benefits of AN 80i for Internet Service Providers:

• It offers a high throughput of 90 Mbps Ethernet PTP.
• It has exceptional long-range capabilities.
• It possesses the lowest in industry end-to-end latency.
• Channel size and speed selections are software-controlled.
• Built-in quality of service controls to prioritize traffic groups.
• TDD or time-division duplex transmission.

2. SAF Tehnika is known for providing technology usable by public and private sector networks. Its technologies are perfect for data as well as voice communications. Its technology gets the credit for being very flexible because it can be configured in several point-to-point topologies and schemes.

The Technology: SAF Freemile 24 FODU is the hallmark of SAF Tehnika point-to-point wireless radio communication. It is a license-free ISM band radio that works on 24 GHz for packet data and voice transmission. It is known for its high availability, interference-free operation, carrier-grade duplex facility without any licensing cost, and easy and quick installation, a traditional ISM radio feature. The users have a trouble-free experience due to the amicable web browser management interface and simple installation process.

Several features offered by Freemile 24 FODU that provide a good reason for users to buy it are:

• 100Mbps Full Duplex Ethernet
• Low interference compared to 2.4 GHz and 5.8 GHz links.
• Hitless Modulation Switching technology that ensures signal availability even in adverse weather circumstances.
• Radio polarization sensor that enables easy installation.
• It comes along with an RF spectrum analyzer.

3. Radwin has introduced a license-free point-to-point architecture that provides high data rate and throughput carrier services to ISPs for multiple end-users from only a single hub site. It is a range of telco-grade products that perform great at a reasonable price.

The Technology: The WInLink 1000 point-to-point radio link combines Ethernet and TDM into a single platform with a speed-delivering capacity of up to 22 Mbps. The radios used have the latest technologies, vast networking capabilities, and effortless installation that reduces operating costs. With low capital expenditure and low operating expenditure, WInLink 1000 has been able to provide enormous possibilities for expansion while maintaining profits.

Customer benefits offered by Radwin WinLink 1000 point-to-point radio:

• Delivering video, voice, and data over one platform reduces access costs.
• Saving leased lines charges.
• Fast deployment with no license costs that increase affordability.
• Heavy reliability and availability due to robust link redundancy and air interface protocol.

4. Performant Networks provides pay licenses and license-free wireless links for real-world conditions concerning outdoor wireless networks. Its R-FLO technology optimizes network paths over fiber links to achieve resilience and quality of service for mixed and completely wireless technologies.

The Technology: R-FLO is the result of several patented technologies. Its aim is to provide Wireless Internet Service Providers with telecom-grade technology that will level the playing field. It targets minimizing labor and maximizing the output from capital invested while at the same time providing a quality of service that boosts revenue.

R-FLO is beneficial for outdoor point-to-point wireless, where performance is largely affected by signal fade or drop. It can monitor the capacity of every link and carry out real-time package transmission, which enables it to groom the traffic and maintain the Quality of Service without the need for a "link down" signal to become aware of such a situation.

Reasons to subscribe to R-FLO by Performant Networks:

• Assurance of performance by a combination of carrier-grade capabilities and ease of use.
• Hardware optimized for use by tier-one ISPs.
• Link degradation, bandwidth adjusting, and backup paths activation capability.
• Dynamic supervision and dynamic configuration capability.

5. Ubiquiti Airfiber-5 is a 5GHz point to point radio gear. Its compact housing gives it an excellent form factor and promises a high throughput of up to 1Gbps over license-free links.

The Airfiber-5 technology is based on the efficient use of the 5 GHz band. It features Power Envelope Tracking Technology, the market leader, and a 1 MHz resolution for the center channel. Airfiber-5 can continuously and accurately control transmit power relative to the band edge, allowing you to choose the part of the band with the most minor interference. xRT feature of a patent-pending technology uses the multi-channel coding scheme to upgrade the transceiver's performance, thereby maximizing your spectrum utilization and link budget. Its links can reach over 100 Km.

Summary of features of Airfiber-5:

• Unique sliding clamp design allows you to assemble mounting hardware before installation.
• Efficient use of the 5 GHz band due to Power envelope tracking technology, as mentioned above.
• Superior Processing due to the use of the proprietary INVICTUS core communications processing engine, whose power, efficiency, and speed amplify its performance.
• Availability of two models viz. Airfiber-5 and Airfiber-5U are used for mid- and high-band frequencies.

Adaptrum Backhaul Point-to-Point solutions

ACRS-1: FCC-certified TV White Space system. ACRS-2. FCC Compliant, low-cost, “Mass Production” solutions will start putting valuable spectrum to work worldwide. Key Features and Benefits:

• 2nd FCC Certified Solution (ACRS-1 April/2012)
• Uses fallow “Beachfront UHF” wireless spectrum (TV White Spaces in the USA)
• Up to 12 Mbps in a single 6 MHz channel
• Uses 95% of each channel (Most Efficient Use of TVWS Vendor Solutions)

Uses 6,7 or 8 MHz channel sizes OFDMA Adaptive Modulation assures quality links Flexible Service Provisioning

• Dynamic Upstream and Downstream Settings & Quality of Service Provisioning

Designed and assembled in the USA

SAF Teknika Point to Point backhaul: Integra

Integra is our next-generation microwave platform that delivers ambitious performance in a compact package that has never been available in a licensed microwave backhaul. Integra’s embedded software takes full advantage of its cutting-edge network processor provided SyncE and 1588v2 PtP support for LTE network builds, header compression, 256-bit AES encryption, and link aggregation for 2+0 deployments. Thanks to a convenient design and its solid functionality, Integra is an industry-unique, right-out-of-the-box microwave system with a superior antenna radiation pattern, industry-leading power consumption (25W typical), and payload capacity of 465Mbps Full Duplex utilizing 1024QAM modulation.

NanoBridge doubles throughput vs. NanoStation.

SAF Lumina Point-to-Point Backhaul link:

We replaced some point-to-point links that were using NSM5 by upgrading to NanoBridge M5 25dBi, and the throughput through the links doubled!

This is an example of how parabolic antennas (like that of NanoBridge), which are more directional than the panel antenna of NanoStation, eliminate signal noise and thereby significantly improve signal and throughput.

WiFi Tower assembly with Rohn pulley and Gin Pole

You have one person on the tower and a second person(s) on the ground. The Rohn pulley attaches to a pole (could be a Gin Pole) near the (current) top of the tower.

The person on the ground hoists the next tower section by pulling a rope through the pulley until the section is all the way at the top, and then the person on the tower fits that section into place.

All the interference on a tower affects the traffic on the ethernet cable

When you have severe interference on a tower, with radio broadcasters, TV broadcasters, etc., Change the ethernet cable to double-shielded (not UBNT ToughCable)

Modulation schemes in wireless backhaul links | QAM rate

• High QAM rate = more throughput
• Lower modulation allows smaller antenna sizes.
• Eband is limited to a QAM rate of 64.

Quadrature amplitude modulation (QAM) is an analog and digital modulation scheme used extensively in wireless digital telecommunication systems. By setting a suitable constellation size, QAM can achieve arbitrarily high spectral efficiencies, limited only by the noise level and linearity of the communications channel.

Antennas: Grid Parabolic and Yagi - construction of

Most grid parabolic antennas are for point-to-point use, and many yagi antennas are made of cast aluminum alloy and coated with a durable powder coat for enhanced protection. The design is such that they make only minimum resistance to wind.