By Sergio Licardie, VP of Advanced Technologies and Innovation at Aviat Networks
The FAS expert system is designed to use several rules to determine if interference is happening in any of the radio links registered for monitoring in the application. As part of the overall design and implementation efforts, Aviat has conducted many laboratory tests that were intended to determine the effects of different types of interferer signals in point to point microwave links. These tests allowed not only for a better understanding of how the performance parameters of the radio link were being affected in the presence of interference; but also to the creation, validation, and refinement of the rules that were implemented in the FAS expert system. As we understand more about the impact interferers can cause to the radio links, the expert system rules will be refined, and new rules will be added. This process will be part of the overall expert system learning and evolution.
- October 19, 2012
- 4G, Chicago, LTE, milimeter wave, NLOS, non-line-of-sight, Non-line-of-sight propagation, PMP, point-to-multipoint, Point-to-multipoint communication, point-to-point, ptp, small cell, unlicensed spectrum
The 4G World show is in 10 days in Chicago, Ill. Speaking of 4G, those of us at Aviat Networks are excited to see what LTE technology will be on display and its promise of 4G speeds for our mobile networks. Confusion will mount as vendors address the myriad capabilities of LTE and the challenges of implementing such an amazing network. Small cell access will be a key topic. Mobile operators need these outdoor-mounted, street-level smaller versions of their LTE basestations to offload some of the overwhelming demand for capacity in metro areas.
One of the critical small cell challenges is backhaul. Imagine the complexity of aggregating traffic from the numerous small cells deployed at key intersections in a big city. Fiber cannot be everywhere and is not economical to operate in most metro locations. There is a lot of buzz around unlicensed Non-Line-of-Sight (NLOS) Point-to-Multipoint (PMP) radios that take advantage of fewer installations than traditional Point-to-Point (PTP) microwave. But be careful of comparisons between PMP and PTP microwave…we hear a lot of hype, promulgated by confusion and relying on fear!
Unlicensed spectrum sounds good but suffers from serious interference issues. NLOS radio capacity drops significantly when trying to transmit around a building. You have to ask: Is the resultant capacity sufficient to serve this specific small cell backhaul need? There are also concerns over latency because LTE has strict delay requirements, and Voice over LTE (VoLTE) will really struggle if latency is not within specification. What about spectrum…is it actually available? Is there only 20 MHz of spectrum available when 40 MHz of capacity is needed?
What about good ol’ reliable and proven Line of Sight (LOS) PTP microwave? With the emergence of millimeter wave PTP radios, capacities up to 1Gbps can be achieved easily over 1-2 kilometers—certainly sufficient for metro small cell distances!
If you have a chance to attend the show, please take the time to ask some of these questions…or else you may be victimized by hype, confusion or fear.
If you would like to hear straight talk on this topic, tune into Aviat’s Small Cell Backhaul webinar. Stay tuned for future blog posts to read about spectrum, capacity, latency, FCC rule changes and technology evolution as the search for viable solutions to the small cell backhaul challenge continues!
Director Business Development
- April 29, 2011
- 4G, Aviat Networks, IEEE, ieee 1588v2, Microwave backhaul, precision time protocol, ptp, sync, synchronization, synchronization over microwave mobile backhaul networks, synchronous ethernet
Synchronization is creating quite a stir in the mobile backhaul industry as operators are wrestling with a variety of synchronization technology options including Synchronous Ethernet (SyncE) and Precision Time Protocol (PTP) a.k.a. IEEE 1588v2. This paper reviews unique microwave backhaul characteristics that need to be taken into account in support of synchronization, and how each particular synch approach can be addressed.