Web Mountain Technologies (WMT) is one of a new breed of manufacturers in the Home Technology market that is building products based upon TCP/IP networking. Web Mountain’s intelligent whole-house server (NetPlace) offers the unique capability of acting as an intelligent Power Line Carrier (PLC) controller – providing features such as time-of-day control, triggered control and “if-then-else” logic, all from a “point-and-click” web browser interface. This Linux-based controller is highly reliable, full-featured and very affordable.

OpenHouse Wiring Solutions

WMT has also been directly involved in the installation of its products, especially in field trials. Being actively involved in this process provides considerable insight into the issues and problems concerning traditional PLC technologies. Thorough testing has revealed that these problems are not the result of issues with the whole-house server, but rather are inherent to the underlying PLC technology.

Some examples of the problems encountered are:

• Phase coupling – With most traditional PLC implementations, there is a nearly absolute need for phase couplers or phase repeaters. Installing a repeater solves the issue of communication over multi-phase systems; however, when they are installed, the communication signals can now interact with similar systems in neighboring homes (assuming the homes share the same transformer). It is quite possible to push buttons in one home and consistently turn lights on and off in the house next door. While there are ways to solve this problem, the solutions are very messy.

• Noise interference – Many devices transmit noise onto the powerline. Noise interferes with the PLC device signals and can cause them to stop working. This problem is particularly evident with audio/video equipment (especially some large screen televisions), laptop power adapters, electric razors, light dimmers, halogen lights, and many other devices. Noise filters are required to remediate the situation. While not individually expensive, the cost of the filters adds up and effectively reduces profit margins for the installer.

• More noise interference – Noise is not only responsible for PLC device communication failure; it can also cause these devices to respond in an undesirable manner. For instance, operating a power tool plugged into a system that is otherwise working properly can cause lights in the house to turn on and off.

• Inconsistent operation – One day the household lighting system works properly, and the next day it doesn’t. Attenuation of the PLC signals over the wiring, combined with noise interference in the circuits, results in inconsistent performance. For instance, lights that are programmed to turn on at night can inadvertently be turned on during the day by noise on the power line.

These are only a few examples of problems that can be encountered when using traditional PLC equipment. However, new PLC technologies are emerging that promise greatly improved system reliability with similar, if not simpler, installation procedures. While traditional PLC devices may be well suited to hobbyists and those who aren’t afraid to roll up their sleeves and make their implementations reliable, companies like Web Mountain Technologies, Powerline Control Systems, and Simply Automated, Incorporated are developing and manufacturing products that provide a more stable, “installer-friendly” alternative.

Introducing Universal Powerline Bus

Universal Powerline Bus (UPB) is a new methodology in powerline communications that is enabling a very stable and ultra-reliable alternative to traditional PLC technologies. Invented and licensed by Powerline Control Systems (, UPB overcomes most, if not all, of the limitations and problems experienced with other PLC technologies. UPB has been tested in a nation-wide field trial in the USA and has proven itself to be > 99.9% reliable.

Web Mountain ( and Simply Automated ( were so impressed by the results of these trials, that they quickly became UPB licensees. Both companies are developing UPB-based devices that are programmable and controllable by Web Mountain’s NetPlace Whole House Server or by other UPB-based controllers.

Whole House Server and UPB Plug-in Modules and Switches

The following are some specification comparisons between UPB and another PLC technology (in this case, X10):
Transmitted signal output level 40 V 5 – 7 V
Transmitted signal frequency 4 – 40 kHz 120 kHz
Date rate 240 bps 120 bps
Full 2Way capability Standard On high end devices
Addresses ~64,000 256 (w/o Extended codes)
Phase coupling Not required Required Except in a small number of large homes

Case Study: Web Mountain has installed UPB devices in approximately 15 homes. With the exception of one outlet in one large house, we installed the devices, powered them up and they worked. The one outlet that didn’t work was fixed by adding a phase coupler. No noise filters were needed and no troubleshooting was required. Only one of the 15 homes (>6500 sq feet) required the UPB phase coupler.

2003 UPB Alpha Test Results

Over the early part of 2003, Powerline Control Systems (PCS) conducted a nation-wide trial of its revolutionary new UPB powerline carrier technology. As a result of these trials, UPB was proven to provide increased communications reliability at a reduced cost over traditional PLC and RF communication technologies. UPB communication is designed to allow remote control of devices (such as lighting, security, HVAC, etc.) over the existing electrical powerline. The main purpose of the UPB Alpha Test was to determine the “real-world” reliability of the UPB communication method in typical U.S. residential environments.

The UPB Alpha Test (Figure 1) was performed by running a Windows-based software program on a personal computer over a six-hour period. Test results (log files) were e-mailed back to PCS for analysis when the test program was finished. The personal computer interfaced to the powerline through a small UPB device called the Powerline Interface Module (PIM) that connected to one of the computer’s serial ports. The software program communicated through the PIM with eight UPB Alpha Test Modules (ATMs) that were plugged into standard electrical outlets throughout the home. These ATMs are comparable to a lamp or appliance module, except they were not intended to control a load. Instead, the ATMs assisted in the logging of performance data.

The normal six-hour test was made up of 24 “sessions” spaced 15 minutes apart. In each session, each of the eight ATM’s was presented with four communication exchanges repeated four times. Therefore, a complete test contained a total communication exchange count of 8 ATM’s x 24 sessions x 4 types of exchange messages x 4 repeats per session per ATM = 3072 communication exchanges.

Figure 1: UPB Alpha Communications Test

Figure 2 shows the number of successful communication exchanges at 1, 2, 3 and 4 attempts, and the number of failures (defined as four failed attempts for one exchange). As is evident from the results, the communication attempts were highly successful. Figure 3 shows the percentage of successful communications attempts.

Figure 2: Communication Reliability (With Coupler)

Figure 3: Final UPB Communication Reliability

As seen in Figure 3, the final UPB communication reliability resulting from the UPB Alpha Test was extremely good.

UPB Characteristics

Signal Strength
UPB’s higher signal strength, coupled with its lower frequency, dramatically reduces the attenuation of the UPB signal over long runs of wire. X10 starts with a lower signal level and has a higher frequency signal, both of which lead to much greater attenuation. PCS has run tests indicating that they can get acceptable performance of UPB devices over greater than one mile of AC wiring.

UPB’s addressing scheme, consisting of 250 Unit ID addresses and 250 Network ID addresses, also solves several problems, including the issue of “talking” to the house next door. Consider that the Unit ID could be compared to X10’s addressing scheme, which allows one home to easily have 250 individually addressable devices. However, call the Network ID a “house address”, and now the powerline system can handle 250 homes with 250 devices in each home. The protocol also includes a network password. A neighbor would need to know both your Network ID and your Network Password in order to interact with your devices, leading to an extremely low probability of interference between homes.

2-Way Communication
The UPB protocol is completely bidirectional. When the transmitter sends a signal, it is expecting an acknowledgement from the receiver. If it does not receive an acknowledgement, it will retransmit the signal up to four times.

Device Flexibility
In addition, devices have tremendous flexibility and can be programmed with some significant features:

* Dimmers can be programmed to enable or disable the dimming function.
* If enabled, dimming fade rates can be set from immediate (snap) to one hour.
* LEDs on the devices can be programmed multiple ways: for example, green if the load is on and off when the load is off, or green for on and red for off.
* Devices can be programmed to send a status report, if they are switched locally, a tremendous feature for intelligent controllers.
* Most devices can be programmed with up to 16 links or “scenes” in the device. This allows one device to be a member of 16 different groups and respond differently depending upon the desired programming.


It is intended that UPB licensees and manufacturers will provide functions and capabilities that are similar to what is currently provided with other PLC technologies. Today, these devices are available for immediate purchase and delivery:

* Wall switches (including dimming)
* 6 and 8 button wall controllers
* 6 and 8 button desktop controllers
* Lamp modules (including dimming)
* Appliance modules
* Input modules (to detect contact closures or low voltages)
* Output modules (to provide contact closures or solid-state outputs)
* Combination input/output modules
* Doorbell or telephone ring detect
* Controlled outlets (or receptacles)
* Fixture dimmer modules
* Fixture relay modules

Web Mountain’s NetPlace Server

Web Mountain’s NetPlace server provides many control functions and features. The unit is designed to reside on a home’s Residential Local Area Network, and allow access from any PC on the network. The server offers capabilities in the following areas:

* Local Area Networking (compatible with wired, wireless and powerline carrier networking).
* Internet access – the unit can optionally act as a NAT router and firewall.
* Intranet and application server – Intranet applications including a Family Calendar, Family Address Book, Recipe Manager, and more – all accessible through a browser interface.
* Digital Content server – storage for digital photos, music and videos, which frees up valuable space on personal computer in the home.
* Backup server – select files and folders from any PC on the network to be automatically backed up at a user selectable time.
* Camera Monitoring – setup network cameras to viewed from any PC on the network or via remote access over the Internet.

Screenshots – WMT NetPlace Server

For the purposes of this document, one of the more important features of the NetPlace server is its UPB Home Control capability. The NetPlace server is the world’s first intelligent standalone UPB controller that allows the user to:

* Set up rooms
* Add new devices and assign them to rooms
* Create links (scenes) for all devices
* Create macros which allow multiple functions to occur simultaneously
o Control devices
o Add time delays
o Run another macro
o Perform conditional commands (if light A is on, don’t turn on light B)
o Send an e-mail based upon conditions
o Send an IR command to control AV equipment along with lighting
o And more ………
* Apply timers to devices and macros

Home Control Screenshots


UPB provides a stable and highly reliable alternative for home control, as compared to other powerline carrier technologies. It is highly affordable, delivering the same performance as many hard wired control systems. For more details on the technology and products, please visit, and