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From the WTF files
On Capitol Hill Thursday, NOAA’s acting chief, Neil Jacobs, said that interference from 5G wireless phones could reduce the accuracy of forecasts by 30 percent. That’s equivalent, he said, to the quality of weather predictions four decades ago. “If you look back in time to see when our forecast scale was roughly 30 percent less than today, it was 1980,” Jacobs told the House Subcommittee on the Environment.
Cameron Kilton from Alpha Wireless and i sit down at the 2019 Indiana ISP meeting and talk about LTE and Wireless operators. Pardon the rough beginning. the room we were in had a flickering light that took me by surprise near the beginning and messed with my rhythm.
ePMP GPS Sync Radio devices that have an onboard GPS contain two banks of flash memory which each contain a version of software.
The version of software last installed onto the device flash memory (using software upgrade procedures) is configured in the Active Bank. This software will be used by the device when the device is rebooted.
One of the biggest tasks on a wireless AP is finding clean channels. Once you find those clean channels, making sure you stay on a clean channel is the next task. ePMP has a feature under tools called eDetect. One of the things this can do is give you an idea of how many devices are on a given frequency.
The ePMP AP you see above is on a 20mhz channel, which is why many home routers and other devices are showing up. If this was on a cleaner frequency it would look like the following.
While eDetect is not a replacement for spectrum analysis, it can give you a pretty good idea of what’s using a particular frequency. Please note, you see the most things on 20MHZ channels because that is what most home routers are set to. If you would like to read up on eDetect in more detail go here: https://community.cambiumnetworks.com/t5/ePMP-Configuration-Management/ePMP-Tools-eDetect-Explained/td-p/42997
Downlink RSSI: -59
Antennas: RF elements Ultra Horns
Downlink Ratio set to 75/25
Question: Why are you not using channel bonding?
A)Having some reliability issues with channel bonding at the moment on the 550 platform.
Question: What was the link like before the horns?
Check out this previous post. (pictures are screwed up for now): http://www.mtin.net/blog/the-addition-of-rf-elements-horns-to-a-ptp550-link/
Recently, there have been some discussions on Facebook about waining support for 2.4GHZ . KP Performance recently published a Future of 5GHZ and beyond blog post. So why all this focus on 5GHZ and why are people forgetting about 2.4?
To answer this question, we need to update our thinking on the trends in networks, not just wireless networks. Customers are demanding more and more speed. Network backbones and delivery nodes have to be updated to keep up with this demand. For anything but 802.11 wifi,2.4GHZ can’t keep up with the bandwidth needs.
One of the significant limitations of many 2.4 radios is they use frequency-hopping spread spectrum (FHSS) and/or direct-sequence spread spectrum (DSSS) modulation. Due to 2.4GHZ being older, the chipsets have evolved around these modulation methods because of age. When you compare 2.4GHZ to 5GHZ radios running OFDM, you start to see a significant difference. In a nutshell, OFDM allows for higher throughput. If you want to read all about the differences in the protocols here ya go: http://www.answers.com/Q/Difference_between_ofdm_dsss_fhss
Secondly, is the amount of spectrum available. More spectrum means more channels to use, which translates into a high chance of mitigating interference. This interference can be self-induced or from external sources. To use an analogy, the more rooms a building has, the more simultaneous conversations can happen without noise in 2.4GHZ we only have 3 non-overlapping channels at 20mhz. Remember the part about more and more customers wanting more bandwidth? In the wireless world, one of the ways to increase capacity on your APs is to increase the channel width. Once you increase 2.4 to 30 or 40 MHz, you do not have much room to deal with noise because your available channels have shrunk.
One of the biggest arguments in support of using 2.4GHZ for a WISP environment is the physics. Lower frequencies penetrate trees and foliage better. As with anything, there is a tradeoff. As the signal is absorbed, so is the available “air time” for transmission of data. As the signal travels through stuff, the radios on both sides have to reduce their modulation rates to deal with the loss of signal. Lower modulation rates mean lower throughput for customers. This might be fine for customers who have no other choice. This thinking is not a long term play.
With LTE especially, traditional thinking is being uprooted. Multiple streams to the customer as well as various paths for the signal due to antenna stacking are allowing radios to penetrate this same foliage just as well as a 2.4 signal, but delivering more bandwidth. These systems are becoming more and more carrier class. As the internet evolves and becomes more and more critical, ISPs are having to step up their services. The FCC says the definition of broadband is at least 25 meg download. A 2.4 radio just can’t keep up in a WISP environment. I am seeing 10 meg becoming the minimum customers want. Can you get by with smaller packages? Yes, but how long can you maintain that as the customer demand grows?
So what is the answer? Cell sizes are shrinking. This is helping 2.4 hold on. The less expensive radios can be deployed to less dense areas and still provide decent speeds to customers. This same trend allows 5GHZ cells to be deployed as well. With less things to go through, 5GHZ can perform in modern networks at higher modulation rates. Antenna manufacturers are also spending R&D to get the most out of their 5GHZ antennas. More money in the pipeline means stronger products. My clients are typically deploying 3.65 and 5GHZ on their towers. LTE is changing RF WISP design and taking the place of 2.4 and 900.
There has been much discussion on the performance of going from an N Series outdoor wireless system to AC. Not all AC is created equal. Right now there is AC Wave 1 and AC Wave 2. Just about all the AC stuff currently in the pipeline for outdoor wireless is wave 1. There is wave 2 indoor gear available, but for a WISP you are interested in the outdoor gear.
So what’s the difference?
For some reading about spatial streams, channel sizes, etc. look at this article https://info.hummingbirdnetworks.com/blog/80211ac-wave-2-vs-wave-1-difference
For the WISP folks who want the Cliff Notes version here are some key differences.
-Wave 1 uses 20,40,and 80 Mhz Channels. Wave 2 can support 80 and 160mhz channels. The 160mhz channel would be two 80mhz channels bonded together.
-Wave 1 can do 3 spatial streams. Wave 2 does 4. This requires an additional antenna to take advantage of wave2. This is a hardware upgrade from wave1 to wave 2.
-Wave 2 supports MU-MIMO. The AP can talk to 4 clients individually at once. The client must also support this, which is a hardware upgrade from wave 1 to wave 2 on both the client and the AP.
The question to ask your vendors is what is the upgrade path if you are using existing AC gear. If you are running AC currently you are most assuredly going to have to replace your AP radios and antennas. Will your existing clients work with the new AC wave 2 aps? An important thing to ask.
iPhone X while sitting in traffic on the west side of Indy.