Once upon a time, cell sites served as little more than passive pass-throughs for phone calls and text messages. Because voice calls and SMS posts did not require much wireless capacity cell sites did not require very robust provisioning. Now that the Internet has gone fully mobile with streaming videos and real-time applications such as VoLTE and IPTV regularly crushing network capacity design parameters, the time to get smart about backhaul and access traffic has arrived. The time for Layer 3 intelligence is now.
In fact, for some time mobile cell sites have transitioned from simple Layer 2 connected sites for 1990s-style mobile phone and data access to multipurpose centers for delivering new, smart device services. However, they can only provide new, smart services if they are built upon Layer 3 technology that offers intelligent handling of wireless traffic. Only IP routing technology is capable of such functionality.
But here comes the catch regarding IP routers providing Layer 3 intelligence at the cell site. With more than 50 percent of the wireless traffic in the world going to and coming from mobile sites through backhaul radio, Layer 3 intelligence must have awareness of microwave networking. And regular routers just do not offer microwave awareness. A new class of device must fill the void left by regular routers that frankly do not have enough “smarts” to deliver Layer 3 intelligence for cell sites that depend on microwave backhaul. A device that combines the best attributes of microwave radios and IP routers.
To provide a closer examination of this issue, Aviat Networks has authored a new white paper—no registration required—that makes the case for Layer 3 intelligence at the cell site. And how to implement a new class of “smart” devices that enable microwave radio awareness with IP routing.
The Case for Small Cell Backhaul
As the search for frequency bands with suitable capacity for small-cell backhaul continues, frequency bands above 50GHz start to appear attractive because they offer both high-bandwidth availability and short range owing to their inherent propagation characteristics. The white paper available at the bottom of this blog examines spectrum in the 57-64GHz range to see whether it can be of use for small cell backhaul.
In many countries, the frequency range 57-66GHz is split into a number of discrete bands with differing requirements and conditions of use and/or licensing. These differences will be highlighted where applicable.
From a global point of view, the use of this spectrum by Fixed Services (FS) is being addressed by the ITU-R in its draft report on Fixed Service use trends in WP5C, which is currently under development and states:
57 GHz to 64 GHz
The radio-frequency channel and block arrangements of these bands for FS are defined in Recommendation ITU-R F.1497.
In 2011, around 700 links were in use in this band in a few administrations. The majority of the links are used for fixed and mobile infrastructure.
The air absorption around 60 GHz is over 10 dB/km. This condition restricts the hop length; on the other hand, the spectrum reuse efficiency is high. This feature makes the band suitable for small cell mobile backhaul.
Clearly, a global reported usage of 700 links would suggest a great deal of underutilization, although with unlicensed use in many countries it is difficult to know whether these figures are accurate or not. Regardless, there are reasons as to why this could be the case, while noting that the ITU-R believes this band has potential for small cell backhaul.
One factor is that this spectrum is not allocated solely to the Fixed Service. In fact, in many countries the Fixed Services have no access to this spectrum at all. A more detailed country-by-country breakdown follows. Please sign up below to receive the entire white paper.[contact-form-7 404 "Not Found"]
This white paper was extremely popular when we featured it in our eNews newsletter recently. Now it’s time to share it with a wider audience.
It talks about how there are several considerations when establishing realistic outage or reliability objectives for and how the effects of long-term and short-term outages differ when it comes to microwave path engineering.