Terms & Definitions

AP: Access Point – A specific RF transmitter on a tower. Can also be used to describe a 2nd WIFI broadcasting device on a customer’s internal network besides the primary wireless router.
ARP Table: An ARP (Address Resolution Protocol) table is a way of mapping known MAC addresses and their associated IP address. As an example, a customer’s router that is acting properly will maintain an ARP table of the MAC addresses of the devices connected to it and the local IP addresses it has assigned to each device.
BER: Bit Error Rate – A ratio of the number of bits received with errors compared to the total bits transmitted. A rapidly increasing BER on the Alignment Tool of a PMP450 radio can be caused by poor signal, chain imbalance, interference, or equipment failure.
BMU: Bandwidth Management Unit – software that manages Powercode’s DHCP server and SNMP monitoring.
CBRS: Citizens Broadband Radio Service – A portion of the 3GHz spectrum from 3550-3700 MHz, previously primarily only usable by military and a few other incumbent providers, that was opened up for general use in 2020, with specific restrictions. In order to operate legally a CBRS device must be registered by a CPI (Certified Professional Installer) who provides registration information to a SAS (Spectrum Access System) which controls the parameters of how the device must operate.
CEA: Customer Experience Agent – No longer common, this is the term for employees at the NOC who directly interact with customers.
Chain Imbalance: A large discrepancy in signal strength between the vertical and horizontal chains of an RF signal. Possible causes aside from equipment failure include an SM hitting the side of an APs Beam (out of sector) or shooting through pine trees whose needles act as a polarizing filter.
CPI: Certified Professional Installer – Responsible for registering and verifying the accuracy of CBRS (3GHz) broadcasting equipment. Devices operating on CBRS must have their information uploaded to the SAS by a CPI in order to operate legally in the US.
CRC: Cylic Redundancy Check – an error-checking technique that ensures the accuracy of transmitted data. High or climbing CRC errors indicate that the data being received doesn’t match what is being sent and can indicate a hardware failure, cross-talk or other interference along the data’s path.
Cross-over Cable: No longer common, a cross-over cable in one where the pairs of wires between the two ends are reversed to permit a direct connection between two computers or devices without the need for a hub or router.
dBm – decibel-milliwatts – dBm is a specific power level whereas dB is relative to some other value. A radio signal of -65 dBm is a specific value. If it worsens by 3dB to a value of -68 dBm the signal has lost 50% of it’s signal strength.
DHCP: Dynamic Host Configuration Protocol – a scalable method of assigning IP addresses to devices on a network. This is the standard connection type used by Bertram and it’s sister companies. See PPPoE and Static IP alternate methods.
DIA: A dedicated internet connection. A connection where there is a dedicated link for a specific customer or account from one of our towers. A more expensive connection that is usually only available for Commercial customers and only if there is sufficient capacity on the tower.
DNS: Domain Name System – Databases which translate domain names (such as google.com) into their corresponding IP address (such as 142.251.32.14). DNS servers are the backbone of the modern internet and can be thought of as an internet phonebook. Bertram has DNS servers of 173.242.94.170 and 192.200.138.6 while other public DNS servers include Google (8.8.8.8) and Cloudflare (1.1.1.1).
Double NAT: A situation that occurs when more than one router on a network is performing Network Address Translation, which can cause issues. For example, a NATted radio basically is acting as a router on the LAN (ethernet) side of the connection and then the customer’s router is also performing NAT for devices on their network. Most commonly causes issues with gaming consoles and with NATted radios a solution is to bridge the radio (after adding the router to the customer’s account).
ETA: Estimated Time of Arrival – most often used when talking about when an installer will arrive (however we should always be giving a larger time window such as AM or PM and not guaranteeing a specific time).
ETR: Estimated Time of Resolution – most frequently used during a maintenance or outage window when describing when we expect an outage or other issue to be fixed. We should generally be vague or give a wide window for when we expect an issue to be resolved.
Fish Tape – A tool used by field technicians to rout cables through walls and conduit.
Full-Duplex – A connection in which data is transmitted in two-directions at once. When looking at the ethernet link on a radio the link should be operating at some variation of full duplex, usually 100Full. See Half-Duplex
Fresnel (freh-nel) Zone – An elliptical path between a RF transmitter and receiver. The higher the frequency the narrower the Fresnel zone.
FTTH: Fiber To The Home – An optical fiber connection directly to a home. aka FTTP (Fiber To the Premises).
GHz – Gigahertz (one billion hertz or cycles per second) – Can be a measure of processing speed or electromagnetic frequency. For our purposes this refers to a specific RF frequency of an RF signal such as 2.4 GHz, 5 Ghz or 3 GHz.
Half-Duplex – A connection in which data is only able to be sent in one direction at once. This severely limits performance since each side of the link can only either transmit or receive data at a time, not both. An ethernet link that is negotiating at half-duplex indicates either an equipment or setting failure on either side or an issue with the cable.
HFC Network or Connection: Hybrid Fiber Coax. Most commonly used by cable companies, a Hybrid Fiber Coax connection consists of a fiber backbone run to a neighborhood and then coax is used for the “last mile” to the home.
Interference: Undesirable signals that interrupt (or interfere) with the transmission of data between two devices or RF broadcasters.
kbps: Kilobytes per second. Aside from referring to old dial up modems, too slow for any modern usage and not generally relevant.
LAN: Local Area Network – A collection of devices in a specific location such as a home or business that are not directly accessible via the wider internet except through some time of gateway like a router. As an example, a customers wired and wireless devices that are connected to their router are on the LAN, while the internet connection comes in on the router’s WAN port.
Legacy – Equipment that is no longer current or being used for new installations. For example, 900 MHz and FSK equipment is considered legacy and is not being installed for new customers.
LOS: Line of Sight – The path between two RF broadcasters such as an AP or SM. An unobstructed line of sight is required for optimal performance.
Mbps – Megabits per second. This is how the speed of our internet plans are measured as well as how link tests between an SM and AP are calculated.
MBps – Megabytes per second (note the upper-case B). 8 bits = 1 byte, so 8mbps is equal to 1 MB per second. This is often how file sizes or downloads are measured which can cause confusion.
MCS: Modulation Coding Scheme is a metric that determines the data rate that is negotiated between 2 broadcasting devices such as an AP and SM based on specific parameters. The closer to 0 the worse the modulation.
MIMO: Multiple-Input Multiple-Output – Originally part of the 802.11n standard (later renamed WiFi 4), MIMO is a method of permitting multiple data signals to be sent and received simultaneously.
mkvsdcauisbest: Mortal Kombat vs DC Animated Universe is best (XL Password)
ms: milliseconds – a measure of time, most frequently used in determining the latency (delay) of data being transmitted between two locations.
NAT: Network Address Translations is a method of modifying packets of traffic as they move from one segment of a network to another, for example between the LAN side of a router and the WAN (internet) side. In this example a router would assign a device on its internal network an internal IP (for example, 192.168.1.50) and packets would include that in the packet header. When sending the packet out to the internet the router would replace that header with the external IP address of the connection (and often a port number). See Double NAT.
NC SC: No Charge Service Call
NLOS: Non Line-of-Sight – 900 MHz equipment (which we no longer install) is considered non-line of sight. Frequencies that permit non line-of sight connections tend to be very limiting in bandwidth capacity.
OORC: Out of Resources Count – On Cambium PMP450 SMs this represents the number of packets that were unable to be transmitted due to running out of resources for NAT. If you see this climbing on a NATted radio you should bridge the radio.
Patch Cable: A short, easily swappable cable that runs between two close nearby devices and for which the individual conductors in the cable remain in the same order. The cable from a PoE injector to the customer’s router is an example of a patch cable.
PoE: Power over Ethernet – a method of delivering DC power via Cat 5 or other twisted-pair ethernet cable on 1 pair of conductors to power a device such as a radio or camera system without having to run independent power.
PPPoE: Point-to-Point Protocol over Ethernet – an alternative method to DHCP of authenticating and assigning an IP address to devices on a network that relies on a username and password. Was used on DCB, but no longer as of March of 2023.
PTP/P2P – Point-to-Point – A specific connection between one broadcasting source and one receiving source. As opposed to a Point to-Multipoint where one broadcasting source such as an AP on a tower connects to multiple receivers. For our purposes a PTP system would be an internal set of radios used to broadcast a signal to another location on a property, for example a feed coming in on a customer’s silo and then a PTP to their house. We generally try to avoid PTP systems and the use of one should usually only be brought up as an option by an installer when onsite.
QoS: Quality of Service – a mechanism to control traffic limits or data priority on a network. With PMP450 SMs the QoS tab enforces limits on the sustained and burst data rates of the connection between the radio and AP on the tower. Routers (such as customer routers) also have QoS settings that can be configured to prioritize certain devices or applications such as gaming or video streaming.
RC: Recovery – Retrieval of Equipment
RSSI: Received Signal Strength Indicator – a measure of signal strength similar to MCS. For our purposes SMs with -60 or better RSSI is generally excellent, -60 to -70 is good, -70 to -75 can be okay depending on the situation and -75 to -80 is poor. Anything worse than -80 will generally result in frequent disconnects.
SAS: Spectrum Access System – A system that dynamically manages the tiered access to the CBRS (3GHz) band. It prioritizes Incumbents (Tier 1 – mostly military) and PAL (Tier 2 – Priority Access Licenses), followed by GAA (Tier 3 – General Authorized Access). All legally operating CBRS equipment must have their information verified by a CPI (Certified Professional Installer) and be registered with the SAS. The SAS is maintained by authorized SAS administrators including Google (our SAS provider), Federated Wireless, Sony and a few others. See CBRS and CPI.
SC: Service Call
Service Loop: An extra length of slack at either end of a cable run for the purpose of permitting future adjustments or re-termination of the cable without having to rerun the cable.
SM: Subscriber Module – A customer’s radio, often accompanied by a dish. In a Point-to-MultiPoint system, the single point is the Access Point (on the tower) and the multiple SMs that connect to the AP are the MultiPoints.
SNMP: Simple Network Management Protocol – a method of exchanging network management information between network devices and among other uses can permit specific commands to be sent to network devices in bulk.
SNR: Signal-to-Noise-Ratio – the relationship between the usable signal and the extraneous (background) noise that is present The worse the SNR, the less useful the RF broadcast is until it eventually can’t be differentiated from the background noise.
SSID: Service Set Identifier – The name of a Wi-Fi network.
UI: Upgraded Install – An upgrade from an older or slower radio to a newer on for the purpose of providing faster speeds. Term no longer used, but common on old DCB tickets.
UPS (Uninterruptible Power Supply): Also known as a battery backup, this device is able to provide stable power to connected devices for a period of time during a brown out or power outage. We have UPSes at most of our tower sites to provide power during outages and customers with unstable power may want to consider one for their own electronics such as router and PoE injector. Also a package delivery service.
WAN: A Wide Area Network, such as the internet. For our purposes, a customer’s router would have a WAN port which would be the connection to the radio (and thus the internet) as opposed to the LAN (Local Area Network) ports which would be their internal network. On an SM the WAN would be the wireless link to the AP and the LAN would be the ethernet link that connects through the PoE to the customer’s router.
WPS: WiFi Protected Setup – An insecure way of connecting devices, especially printers to a WiFi network without the need for a WiFi password. A major security flaw was found in 2011 that permits it to be brute forced and as a result we do not enable WPS on our managed routers.