Mesh Network Meets the Telephone

We now have the capability to use VOIP (Voice Over IP) telephony over the mesh network, and even have a functioning PBX system with voicemail installed. It is very simple to use. Some of us have purchased Grandstream 1620 0r 1625(POE) telephones from Amazon or other sources. These  phones are simply office style desk telephones. They run about $50. Others are using “Softphones” which are software programs you run on your computer that lets your computer act like a telephone. You can use either an inexpensive USB headphone/mic, or simply use your build in speakers and microphone. To use the PBX system we must first set up the account for you. We’re all using our callsigns as our extension numbers, so it will be easy to remember extension numbers. For example, to call me at home, you simply dial K6BPM, or to call me at my office, you dial K6BPM2. This make is very simple to use. Setting things up on your end is simple. If you are using a Grandstream phone, you just plug it in and that’s it. If you are using a Softphone, you just need to give it an account name and password, and you’re in. You’ll have all the niceties you’re use to like call waiting, missed call lists, notifications for new messages, etc. If you want phone repairs, Pro Phone Repairs of Albuquerque’s Instagram need to be chekced. Using voicemail is exactly like what you are probably used to using at your job, or maybe even your home. You call in, enter your password, then check your messages. You have all the tools available to you as you do on commercial voicemail systems like recording greetings, message forwarding, mailbox folders, etc. Surprisingly, it all works pretty well! As we get everything dialed in, I expect it will get better and better! If you haven’t yet got on the mesh, maybe this will interest you! – Brian – K6BPM

Keeping Time on the Mesh Network

These days we’re all used to our computers always having the correct time. Periodically, they simply connect to the Internet and get the correct time from an Internet time (NTP) server. Our local mesh network is designed to work “off-the-grid” without an Internet connection. This is a problem. All of our nodes and devices running services need to know the correct time. MeshChat servers record the date and time anyone posts a message. So does the SBARC mesh website. So how do we keep all these devices synchronized with the correct time? To address this problem, I am building a Raspberry Pi (RPi) based stand-alone NTP Stratum 1 server. Since it cannot connect to the Internet to update the time, I decided to synchronize it using GPS. Adafruit makes a perfect add-on board for this that plugs into the GPIO header that offers full access to GPS signals including the time. So every few seconds, the Raspberry “reads” the incoming GPS signals from whatever satellites it can “see” and adjusts it’s internal time. Normally, to get a good GPS “fix”, we need to connect to at least 5 or more satellites. However we can get an extremely accurate time reading from just one satellite. To allow other devices on the mesh to synchronize the time, a little programming is required on the RPi so it can be used as an NTP Stratum 1 server. It operates exactly the same as a time server does on the Internet. So instead of using something like as a time server, we can use k6bpm-ntp.local.mesh as the time server for our mesh connected devices. Connection speeds will vary node to node. While the RPi will be accurate to the millisecond, the various nodes using it may be off by a second or two because of latency delays due to connection speeds. But that’s okay. We don’t need millisecond accuracy for our purposes. In fact, we can be a minute off and it won’t hurt anything. I will probably locate this at my house when I am through testing it. I have a very fast connection (25Mbps+) to the Gibraltar nodes there. Everyone is free to use it for their “NTP Server” when setting up their local nodes.

Nanostation Shielding and Mounting

I installed my NanoStation today at my home QTH using one of these kits from RFArmor. I was really impressed with the build quality and general utility. Not only does if provide RF shielding for your Nanostation, it is also a mounting system with options for mast mount (which I used) or wall mount. All mounting hardware is included. According to the manufacturer, these shields provide a lower noise floor, cleaner signal, superior signal to noise ratio, fewer wireless retries and errors, higher sustainable air rates, and up to 50% increase in performance. They are $27.95 and available here:

Ubiquiti Videos

I found some great videos at the Ubiquiti site that cover a lot of interesting topics about using AirMax equipment. Our Nanostations and Rockets are “AirMax” products. Although these videos are not specifically about devices using the AREDN firmware, they still explain a lot of concepts we share with the factory firmware equipped nodes.

Mesh Network Status – April 9th, 2016

Our three nodes at Gibralter Peak are working extremely well. We have members linking up from Goleta to Carpinteria and several points in-between. There are about 5 nodes online now and another 5 or so coming up soon! The node for the club station is programmed and ready to go, but installation on the mast was delayed because of rain. We still need to raise funds to build out the La Vigia site on the Mesa. We need 2 or 3 Ubiquiti Nanostation nodes there and a ToughSwitch network switch. All the equipment will cost us about $400 and any help our members can offer will be greatly appreciated. If you can help with a donation please click here. Our next step will be to connect over the mountain to the Santa Ynez Valley. We’re very lucky to have access to all the great repeater sites that Bill W1UUQ has spent many years cultuivating. This enables is to to some great things with emergency and general communications of all kinds and we hope to utilize these assets wisely to enhance our communications abilities.

Node Naming Conventions

We are encouraging users to use a common naming convention when naming devices on the local mesh network. This will help others identify your node and pass along some useful information about your installation. Here is an example for my node at my office downtown is: K6BPM-DLV-NSM2–N60 This breaks down to: K6BPM -> my callsign. Always comes first. DLV -> something to ID this node. In this case DLV stands for De La Vina NSM2 -> the type of equipment, a Nanostation M2 N60 -> the direction it is pointing North and the radiation pattern is 60° (standard for a NSM2) So my link will show up as http://K6BPM-DLV-NSM2-N60.local.mesh on the node status page.