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39 GHz Spectrum
Frequently Asked Questions
Have You Considered 39 GHz Lately?

What are the benefits of 39 GHz?

• Licensed - Only licensed spectrum provides operators with the protection of interference-free operation. Valuable data requires uninterrupted high-speed data transport that is not guaranteed in unlicensed bands.
• Cost and capital equipment - Equipment supporting 39 GHz is carrier class and readily available at attractive values. Until large inventories of latest generation equipment are installed, 39 GHz offers unsurpassed price/value relationships.
• Fast to install - Avoiding the FCC license application process can save weeks or months in many cases. 39 GHz licensed transmission capacity can be available within a few days of your request. We can quickly and easily provide professional installation of your radios.
• Uncrowded - Relatively few holders of 39 GHz spectrum mean that frequency coordination is simple and fast. This compares favorably with both unlicensed bands as well as common carrier bands where numerous geographies are reaching saturation.
• High capacity - Each channel of 39 GHz spectrum has 100 MHz available and can carry up to 622 Mbps (OC-12). More typical applications are between 45 Mbps and 155 Mbps (DS-3 to OC-3), but operators using 39 GHz will have significant additional capacity should the need arise.
• Suitable for metropolitan areas - Fast speeds, rapid installations and readily available spectrum make 39 GHz an ideal frequency for metropolitan areas. It is these areas where unlicensed and certain licensed frequency engineering challenges are the greatest.

How does FCC-licensed 39 GHz compare to unlicensed frequencies such as U-NII band?

• Interference - The FCC does not guarantee that unlicensed frequencies will be free from interference. In other words, any number of users may use unlicensed frequencies and harmful interference is a strong possibility. On the other hand, licensed frequencies are assigned to only one user at a time and the FCC can prosecute unauthorized users. Typically speaking, the more important the application, the more important freedom from interference and the use of licensed links become.
• Capacity - Typically, unlicensed frequencies have less bandwidth available and, in order to protect from interference, less of that bandwidth is utilized. The 39 GHz frequencies have substantial bandwidth available and can run speeds of up to OC-12 (622 Mbps).

How does FCC-licensed 39 GHz compare to use of common carrier frequencies such as 18 GHz and 23 GHz?

The primary differences are the length of time required for the license process and the availability of equipment on the secondary market. You can save many weeks, or even months in some instances, compared to the licensing process for 18 and 23 GHz. In addition, equipment servicing the 39 GHz market is carrier class and readily available at very good values due to an imbalance in supply and demand.

How far can a 39 GHz link reach?

It depends on the rain region. You can estimate the link length at a given reliability level using our distance table. Generally speaking, two miles is a good working assumption.

How does rain affect my link?

Service outages can be caused by heavy rain. Rain outages occur when raindrops attenuate the microwave signal power below a usable level. The attenuation becomes significant as the size of the raindrops approaches the wavelength of the signal. A properly designed link will have sufficient fade margin to accommodate even heavy rain periods to maintain availability greater than 99.999% (approximately 5 minutes of outage per year).

Do I need to perform a line-of-sight analysis?

Yes. As with all other microwave bands, you do need line-of-sight from both ends of a fixed wireless link. The line-of-sight analysisdetermines whether the path clears a portion of the first Fresnel zone over any potential obstructions (e.g. buildings, trees, hills, etc).

How much does the radio equipment cost?

Radio equipment for 39 GHz is mature and, due to an imbalanced inventory situation, is available at very good values. Exact costs for particular capacity radios are fluid. However, we believe that a (4) T-1 (6 Mbps) link (two new radios) can be purchased for as little as $500, a DS-3 (45 Mbps) link (two new radios) can be purchased for around $3,500 and a 100 Mbps link (two new radios) can be purchased for well under $20,000.

Is frequency coordination required?

Yes. However, since there are very few licensees and large number of available frequencies, the length of time to conduct the frequency coordination will typically take just two to 15 days and the average is around 10 days. You can save weeks, or even months in some instances, compared to the licensing process for 18 and 23 GHz.

How fast can a link be established?

A transmission capacity agreement for 39 GHz licenses can be established in as little as a day. The length of time to conduct the frequency coordination will typically range from two to 15 days depending on the specific link with the average time being around 10 days. In most cases, it takes several days to install the equipment. This compares very favorably with 18 GHz and 23 GHz links. For example, a 23 GHz link can take up to six months to receive FCC permission to operate.

How much data can be put over a link?

It is possible to utilize radios that provide OC-12 (622 Mbps) capacity although OC-3 (155 Mbps) is more typical. Radios with capacity from T-1 (1.5 Mbps) to OC-3 (155 Mbps) are readily available.

What is the chance of users suffering interference?

Unlike unlicensed spectrum that has zero protection, 39 GHz licensed spectrum has all the protection afforded by the FCC and can be further monitored for frequency protection. Therefore, the probability of interference is infinitesimally small and the probability of chronic interference is zero.

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