Universal powerline bus
Encyclopedia
Universal powerline bus (or UPB) is a protocol for communication
among devices used for home automation
. It uses power line
wiring for signaling and control.
UPB was developed by PCS Powerline Systems of Northridge, California and released in 1999. Based on the concept of the ubiquitous X10
standard, UPB has an improved transmission rate and higher reliability. While X10 without specialty firewalls has a reported reliability of 70-80%, UPB reportedly has a reliability of more than 99%.
data between UPB devices.
While in the X10
protocol this digital data is encoded onto a 120 kHz
carrier which is transmitted as bursts during the relatively quiet zero crossing
s of the 50 or 60 Hz
AC alternating current
waveform
, the UPB protocol works differently.
The UPB communication method consists of a series of precisely timed electrical pulses (called UPB Pulses) that are superimposed on top of the normal AC power waveform (sine wave). Receiving UPB devices can easily detect and analyze these UPB Pulses and pull out the encoded digital information from them.
UPB Pulses are generated by charging a capacitor to a high voltage and then discharging that capacitor’s voltage into the powerline at a precise time. This quick discharging of the capacitor creates a large “spike” (or pulse) on the powerline that is easily detectable by receiving UPB devices wired large distances away on the same powerline.
UPB Pulses are transmitted in a special region toward the end of the AC half-cycle known as the UPB Frame. This region was selected due to its relatively low noise characteristics and for other attributes that make it an optimum position for powerline communications. UPB Frames are synchronized to the low-to-high transition of the AC waveform (known as the AC zero-crossing point) such that one Frame starts T/Frame milliseconds after the zero crossing and the other Frame starts 8,333 milliseconds (one half-cycle at 60Hz) after the first one.
The simplest controllers are plug-in controllers that are recommended for a moderate amount of switches and devices as it becomes cumbersome to control a wide range of devices.
More sophisticated controllers can control more units and/or incorporate timers that perform pre-programmed functions at specific times each day. Units are also available that use passive infrared
motion detectors or photocells to turn lights on and off based on external conditions.
Finally, whole house home automation controllers can be fully programmed. These systems can execute many different timed events, respond to external sensors, and execute, with the press of a single button, an entire scene, turning lights on, establishing brightness levels, and so on.
Power line communication
Power line communication or power line carrier , also known as power line digital subscriber line , mains communication, power line telecom , power line networking , or broadband over power lines are systems for carrying data on a conductor also used for electric power transmission.A wide range...
among devices used for home automation
Home automation
Home automation is the residential extension of "building automation". It is automation of the home, housework or household activity. Home automation may include centralized control of lighting, HVAC , appliances, and other systems, to provide improved convenience, comfort, energy efficiency and...
. It uses power line
Electric power transmission
Electric-power transmission is the bulk transfer of electrical energy, from generating power plants to Electrical substations located near demand centers...
wiring for signaling and control.
UPB was developed by PCS Powerline Systems of Northridge, California and released in 1999. Based on the concept of the ubiquitous X10
X10 (industry standard)
X10 is an international and open industry standard for communication among electronic devices used for home automation, also known as domotics. It primarily uses power line wiring for signaling and control, where the signals involve brief radio frequency bursts representing digital information...
standard, UPB has an improved transmission rate and higher reliability. While X10 without specialty firewalls has a reported reliability of 70-80%, UPB reportedly has a reliability of more than 99%.
Power-line carrier control overview
Household electrical wiring such as Romex or BX is used to send digitalDigital
A digital system is a data technology that uses discrete values. By contrast, non-digital systems use a continuous range of values to represent information...
data between UPB devices.
While in the X10
X10 (industry standard)
X10 is an international and open industry standard for communication among electronic devices used for home automation, also known as domotics. It primarily uses power line wiring for signaling and control, where the signals involve brief radio frequency bursts representing digital information...
protocol this digital data is encoded onto a 120 kHz
Hertz
The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....
carrier which is transmitted as bursts during the relatively quiet zero crossing
Zero crossing
Zero-crossing is a commonly used term in electronics, mathematics, and image processing. In mathematical terms, a "zero-crossing" is a point where the sign of a function changes Zero-crossing is a commonly used term in electronics, mathematics, and image processing. In mathematical terms, a...
s of the 50 or 60 Hz
Hertz
The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....
AC alternating current
Alternating current
In alternating current the movement of electric charge periodically reverses direction. In direct current , the flow of electric charge is only in one direction....
waveform
Waveform
Waveform means the shape and form of a signal such as a wave moving in a physical medium or an abstract representation.In many cases the medium in which the wave is being propagated does not permit a direct visual image of the form. In these cases, the term 'waveform' refers to the shape of a graph...
, the UPB protocol works differently.
The UPB communication method consists of a series of precisely timed electrical pulses (called UPB Pulses) that are superimposed on top of the normal AC power waveform (sine wave). Receiving UPB devices can easily detect and analyze these UPB Pulses and pull out the encoded digital information from them.
UPB Pulses are generated by charging a capacitor to a high voltage and then discharging that capacitor’s voltage into the powerline at a precise time. This quick discharging of the capacitor creates a large “spike” (or pulse) on the powerline that is easily detectable by receiving UPB devices wired large distances away on the same powerline.
UPB protocol
While transmitting, one UPB Pulse is generated each half-cycle of the 60Hz AC electrical power cycle. The generation of each UPB Pulse is precisely timed to occur in one of four predefined positions in the half-cycle of the AC powerline. The position of each UPB Pulse determines its value as either 0, 1, 2, or 3. This method of encoding data as a relative position of a pulse is a well-known and used method in digital communications known as Pulse Position Modulation (PPM). Since each UPB Pulse can encode two bits of digital information and there are 120 AC half-cycles per second (at 60Hz), UPB communication has a raw speed of 240 bits per second. Although this speed isn’t fast enough for doing high bandwidth applications it is perfectly adequate for doing command and control communication.UPB Pulses are transmitted in a special region toward the end of the AC half-cycle known as the UPB Frame. This region was selected due to its relatively low noise characteristics and for other attributes that make it an optimum position for powerline communications. UPB Frames are synchronized to the low-to-high transition of the AC waveform (known as the AC zero-crossing point) such that one Frame starts T/Frame milliseconds after the zero crossing and the other Frame starts 8,333 milliseconds (one half-cycle at 60Hz) after the first one.
Controllers
UPB controllers range from extremely simple plug-in modules to very sophisticated whole house home automation controllers.The simplest controllers are plug-in controllers that are recommended for a moderate amount of switches and devices as it becomes cumbersome to control a wide range of devices.
More sophisticated controllers can control more units and/or incorporate timers that perform pre-programmed functions at specific times each day. Units are also available that use passive infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
motion detectors or photocells to turn lights on and off based on external conditions.
Finally, whole house home automation controllers can be fully programmed. These systems can execute many different timed events, respond to external sensors, and execute, with the press of a single button, an entire scene, turning lights on, establishing brightness levels, and so on.
Things to consider
UPB is a powerline carrier technology which can be affected by devices on the powerline. However with the advance of the technology to Generation II there are only a few items that can affect the UPB Signal. The engineering team created specific devices to isolate these items.See also
- INSTEONINSTEONInsteon is a system for connecting lighting switches and loads without extra wiring. INSTEON is a dual-band mesh home area networking topology employing AC-power lines and a radio-frequency protocol to communicate with devices...
- dual-band mesh topology invented by SmartLabs, Inc. - X10 (industry standard)X10 (industry standard)X10 is an international and open industry standard for communication among electronic devices used for home automation, also known as domotics. It primarily uses power line wiring for signaling and control, where the signals involve brief radio frequency bursts representing digital information...
- X-10 industry standard home automation protocol - IEC 61334IEC 61334IEC 61334 is a standard for low-speed reliable power line communications by electricity meters, water meters and SCADA.It is also known as S-FSK, for "spread frequency shift keying" and was formerly known as IEC 1334 before IEC's most recent renumbering...
a similar standard invented for wide-area power line communication.