Metasys® System Extended Architecture Application Note

Application Note Issue Date October 24, 2006

© 2006 Johnson Controls, Inc. www.johnsoncontrols.com Code No. LIT-1201730 Software Release 2.1

Metasys® System Extended Architecture Wireless Network

Metasys System Extended Architecture Wireless Network ..............3

Introduction......................................................................................................... 3

Key Concepts...................................................................................................... 4

Wireless Networking Overview ......................................................................................... 4 Metasys System Extended Architecture Wireless Network............................................... 6 Configurations ................................................................................................................... 7 General Design Guidelines ............................................................................................. 10 Wireless Equipment Setup Guidelines............................................................................ 11 Wireless Issues and Risks .............................................................................................. 14 Security Mechanisms ...................................................................................................... 16 Choosing Wireless Devices and Equipment ................................................................... 16 Performance Expectations .............................................................................................. 18

Appendix - Procedures .................................................................................... 19

Installing the AP ..............................................................................................................19 Configuring the AP .......................................................................................................... 19 Installing the Wireless Bridge.......................................................................................... 26 Configuring the Wireless Bridge...................................................................................... 26 Configuring Wireless Clients ........................................................................................... 29 Checking Associations .................................................................................................... 30 Checking Signal Quality .................................................................................................. 33

Appendix - Troubleshooting............................................................................ 37

Problems and Recommendations ................................................................................... 38 Interference - Wireless Spectrum Sweep........................................................................ 38 Wireless Spectrum Interference...................................................................................... 39 Bandwidth Limitations ..................................................................................................... 39 AP Overview Summary ................................................................................................... 40 Activity Logs .................................................................................................................... 40

Metasys System Extended Architecture Wireless Network Application Note

2

Outdoor AP or Bridge Configuration ............................................................................... 43 Servicing Equipment ....................................................................................................... 43

Appendix - Tested Equipment ......................................................................... 44

Hardware and Software .................................................................................................. 44 Packet Analyzers ............................................................................................................ 44


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Metasys System Extended Architecture Wireless Network

Introduction The Metasys® system extended architecture wireless network application provides a solution to allow the Metasys system extended architecture to communicate over a Wireless Local Area Network (WLAN). The wireless network allows a Network Automation Engine (NAE) to communicate wirelessly with a Web browser and/or any device with an Internet Protocol (IP) address in the same way that it communicates over a wired Ethernet network. For situations in which wired Ethernet coverage is not desired or feasible, the wireless network enables an NAE to communicate with a Web browser without using a wired Ethernet network. The application of a wireless network also allows a user to access the User Interface of the NAE from a wireless laptop computer (as shown in Figure 2) while walking around the building. This document is not designed to teach wireless networking principles. This document is intended to assist Johnson Controls® operations personnel and customers who want to make portions of their Metasys system extended architecture communicate on the WLAN. This document describes how to set up a Personal Computer (PC) or an NAE in a wireless environment, and assumes that a person performing this configuration has an Information Technology (IT) resource available to install and configure wireless equipment. This document includes: • supported wireless topographies • general wireless design guidelines • procedures to configure wireless equipment This document also describes basic areas of troubleshooting and provides a list of wireless products tested by Johnson Controls. Note: Unless otherwise specified, the term NAE applies to both the Network Automation Engine (NAE) and the Network Integration Engine (NIE).


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Key Concepts Wireless Networking Overview

Building owners are faced with an increasing number of decisions and options related to wireless technologies. Wireless products, applications, and services in the area of building operations, mobile communications, and management, as well as high-speed data, are available and have proven to enhance building performance. A WLAN can integrate with and extend the wired LAN.

The Radio Frequency (RF) environment within a building is an asset, and management of this environment is critical to successful wireless performance. Planning for the impact of current and future wireless applications is an important consideration for the building owner.

Competence in wireless networking is critical to any wireless solution. Only trained and knowledgeable personnel should install and commission wireless equipment.

Table 1 provides a summary of wireless definitions related to wireless networking.

Table 1: Wireless Terms and Definitions Term Definition 802.11 A set of specifications (includes all suffixes) for definition of a wireless LAN. This

includes Frequency Hopping Spread Spectrum (FHSS), Direct Sequence Spread Spectrum (DSSS), and infrared communication techniques.

802.11a A wireless communication protocol standard running at 5 GHz with a maximum baud rate of 54 Mbps (turbo mode 108 Mbps). Nominal penetration of less than 150 feet. Potentially less interference in the 5 GHz band from other wireless devices, radios, and microwaves.

802.11b A wireless communication protocol standard running at 2.4 GHz with a maximum data rate of 11 Mbps and a nominal penetration of less than 300 feet.

802.11g A wireless communication protocol standard running at 2.4 GHz with a maximum data rate of 54 Mbps. Nominal penetration of less than 300 feet.

Access Point (AP) This device is a wireless-to-wired bridging device for one or many wireless devices. Client devices (for example, laptop computers) associate themselves to an AP. Similar to cellular technology, if the client device roams, the client disassociates from the AP and re-associates to another AP as needed.

Broadband A large collection of frequencies that travel on a single wire. For example, cable TV is broadband.

Building Automation System (BAS)

A generic term used for systems like the Metasys system. BAS encompasses all aspects of building control including Heating, Ventilating, and Air Conditioning (HVAC), Fire, Security, and Lighting.

Commercial Off The Shelf (COTS)

Hardware products that are ready-made and available for sale.

Continued on next page. . .


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Term (Cont.) Definition dBm Decibel referenced to one milliwatt.

dBm is a unit of power measurement where a strong signal is in the range of –50 to –70 dBm, where –50 dBm is the stronger signal.

Dead Spot An area of a facility served by a utility (for example, wireless communication) that has inadequate or no available coverage. Also referred to as a Cold Spot (see Hot Spot).

Ethernet Network Port The port on the NAE used to connect the NAE and User-Interfaced (UI) devices. Hot Spot A term used to identify a location where Wi-Fi protocol service can be accessed,

for example, to provide wireless connection to the Internet. InnerWireless® Distributed Antenna System (DAS)

The InnerWireless DAS provides an in-building distributed antenna system.

Megabits Per Second (Mbps)

A measure of the capacity of a media for data transmission. A typical hardwire Ethernet network can operate at 10 or 100 Mbps. A typical dial-up Internet connection is less than 56,000 bits per second (bps).

Radio Any device that communicates to another device using RF communication. Radio Frequency (RF) A generic reference for any communication devoid of physical wires. Roaming The ability to move from one AP’s area of coverage to another seamlessly,

without loss of signal or quality. This is similar to a cell phone roaming. Site Survey The procedure a wireless installer uses to verify the existence of a location for

wireless coverage or interference. SSID/ESSID Service Set Identifier/Extended Service Set Identifier. An up to 32-character,

unique identifier used to allow wireless devices to communicate with other devices on the wireless network that uses the same SSID/ESSID.

Wi-Fi Protected Access (WPA)

A Wi-Fi protocol standard designed to improve upon the security of WEP.

Wired Equivalent Policy (WEP)

An encryption procedure to protect or increase the security of a wireless transmission. WEP uses an encryption key to mathematically encrypt the transmitted data.

Wireless Fidelity (Wi-Fi) Protocol

Another name for the 802.11 suite of protocols. This term can also refer to an Interoperability standard that defines a specific level of testing to verify IEEE 802.11 conformance.

Wireless Bridge A device that converts Ethernet/IP wired packets to wireless packets and vice versa.

Wireless Local Area Network (WLAN)

A Local Area Network (LAN) that is wireless versus a hardwired LAN.

Wireless Policy A set of rules enforced by the local IT department that dictates who can access the WLAN and the types of wireless devices allowed at the site.

Find additional information on the wireless band at: http://wireless.fcc.gov/rules.html.

Also, information on the wireless band that deals with the future and risks of WLAN is at: http://www.wi-fiplanet.com.


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Metasys System Extended Architecture Wireless Network The Metasys system extended architecture wireless network solution allows an NAE to communicate over a wired LAN, a wireless LAN (WLAN), or a combination of the two. The wireless network can be accessed anywhere a wireless signal is available and in situations where it may not be possible or cost effective to access the wired LAN.

For example, if an office building only has Ethernet access on office floors and the NAE is in the basement, users can access the NAE over the WLAN rather than running an Ethernet cable to the NAE or installing the NAE on the office floor and running N2 cables to the NAE.

The WLAN for this application uses the Institute of Electrical and Electronics Engineers, Inc. (IEEE) 802.11 suite of protocols. This suite of protocols, also called Wi-Fi protocol, can be used to refer to an interoperability standard that defines a specific level of testing to verify 802.11 protocol conformance.

Note: The wireless Metasys network has only been tested with 802.11b. See the Appendix - Tested Equipment section of this document.

The wireless industry currently envisions wireless communication complementing wired communication, not replacing it. While this vision could change as wireless technology evolves, we anticipate that Building Automation Systems (BASs) will always be a wired/wireless hybrid system. Wireless systems are less expensive to install for retrofit applications and more flexible for users than wired systems. However, wired systems are more reliable for mission critical operations like fire controller panels and smoke control systems.


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Configurations There are two wireless network configurations to consider. The first wireless network configuration uses APs and wireless bridges as the wireless infrastructure. The second configuration uses APs, wireless bridges, and a wireless infrastructure system. The second configuration detailed in this document uses an InnerWireless Distributed Antenna System (DAS).

Wired System The Metasys system can use a wired LAN, a wireless LAN, or a combination of the two. Figure 1 shows an example of a typical wired network.

WAN

Firewall

Field Bus(N2)

Web Browseron a Desktop

Computer

Ethernetnetwork

Wire

d_C

onfig

Web Browser on aLaptop Computer

NAE

ADS Serverwith SCT

Figure 1: Wired LAN Configuration Diagram


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Metasys System Extended Architecture Wireless Network Figure 2 shows an example of a Metasys system on a wireless network and how a user could access the ADS from a Web browser on a desktop computer or a wireless laptop computer. In this example, the NAE sends data to the Application Data Server (ADS) using the WLAN. Table 2 describes the components of the Wireless network.

WAN

Firewall

Field Bus(N2)


Computer

Ethernetnetwork

Wire

less

_Con

fig

WirelessBridge

AccessPoint

Wireless

Wireless

WirelessEthernet

Card


NAE

= Wireless Antenna

ADS Serverwith SCT

Figure 2: WLAN Configuration Diagram


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Metasys System Extended Architecture Wireless Network with Wireless Infrastructure System The Metasys system can be enhanced by using a wireless infrastructure system, which provides uniform and secure wireless coverage throughout the building and makes it possible to cover a larger building with fewer APs. Refer to the Johnson Controls Network Integration Solutions Overview Product Bulletin (LIT-12011229) for further information on the wireless infrastructure systems available through Johnson Controls.

The InnerWireless Distributed Antenna System referenced within this document provides an in-building distributed antenna system. Figure 3 shows an example of an InnerWireless DAS configuration. Table 2 describes the components of the Metasys system extended architecture wireless network with the InnerWireless Distributed Antenna System.

WAN

Firewall

Field Bus(N2)


Computer

Ethernetnetwork

FIG

:inne

rwire

less

das_

conf

ig

Wireless

InnerWireless Antenna

WirelessEthernet

Card


NAE

= Wireless Antenna

AccessPoint

Field Bus(N2)

WirelessBridge

NAE

Wireless

ADS Serverwith SCT

Figure 3: InnerWireless Distributed Antenna System (DAS) Configuration


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Table 2: Metasys System Extended Architecture Wireless Network Components Component Example* Description AP (AP) Cisco® 1200 AP Provides wireless access to the wired LAN for

one or many wireless devices. Client devices (for example, laptop computers) associate themselves to an AP. As with cellular technology, if the client device roams, the client disassociates from one AP and re-associates to another AP as needed.

Wireless Bridge Cisco 350 Workgroup Bridge Converts Ethernet network wired packets to wireless packets and vice versa.

Wireless Ethernet Card

Cisco 350 Wireless LAN Client Adapter

Allows a computer to communicate with an AP.

Wireless Infrastructure System

InnerWireless Distributed Antenna System by Johnson Controls, Inc.

A wireless infrastructure system that provides uniform and secure wireless coverage within a building.

* For a list of approved vendors, see the Appendix - Tested Equipment section in this document.

General Design Guidelines This section provides an overview of the steps a person trained in this field must perform to set up a wireless network. Do not try to design the wireless network without the input of the customer IT department, a wireless solutions company, and/or other wireless resources.

The first step in a wireless installation is communication with the IT department. Determine if there is an existing wireless infrastructure and, if so, determine if there is a wireless policy.

The next step is to determine if the network is going to be a wireless infrastructure installation (Figure 3) or a typical AP installation (Figure 2).

• For a wireless infrastructure installation, contact your Johnson Controls wireless representative to perform a site survey, verify wireless configuration, and provide additional installation instructions for interoperability with the Metasys system.

• A typical AP installation requires a site survey and a thorough understanding of antenna placement, hot/cold spots, interference, security, general spectrum management, channel assignment, overlapping channels, interference, and a bandwidth usage estimation to determine if there is adequate bandwidth for a Metasys network.

Note: Some AP manufacturers (like Cisco Systems, for instance) provide features that allow you to prioritize Metasys system data traffic and increase the performance of the Metasys system, even if the overall bandwidth usage is high.


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Note: We highly recommend that the customer site implement and maintain a wireless policy once a wireless installation is complete.

The IT department also provides the necessary IP addresses and networking information required to set up a wireless Metasys network.

Third, install and commission the Metasys system. Before trying to communicate on the WLAN, first verify that the Metasys system works properly when a computer is directly connected to the NAE/NIE using the Ethernet port. Refer to the Installing the NAE/NIE Technical Bulletin (LIT-1201161).

The final step is to have your wireless network resource set up and configure the wireless equipment (see Wireless Equipment Setup Guidelines). Once done, verify that the Metasys system and the wireless components are operating correctly. Initially, verify operation over several days and at various times throughout the day.

Wireless Equipment Setup Guidelines IMPORTANT: Only trained personnel should set up wireless equipment. The information in this application note is for informational purposes only and should not be considered a substitute for a wireless networking resource.

The procedures to set up wireless devices may vary as new features and firmware upgrades are released. Devices set up incorrectly can have drastic effects on system performance.

Johnson Controls recommends that you use the equipment at the firmware revision levels as specified in the Appendix - Tested Equipment section of this document. Equipment from lower cost vendors may result in performance and reliability degradation. Use other equipment at your own risk.

The key configuration parameters for a wireless device are: Service Set Identifier (SSID), channel, transmit power, data rates, IP address, and encryption (WEP, WPA, and EAP). See Table 3 for recommended settings of these parameters.

Note: Equipment may vary by manufacturer. Consult the wireless equipment technical literature to set these parameters.


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Table 3: Setup Parameters Feature Description Setting SSID A unique identifier that allows wireless

devices using the same SSID to communicate.

Set one unique SSID for use by all of the wireless Metasys system devices in your facility. Note: Other SSIDs can exist in the building for unrelated wireless devices.

Channel Avoid using APs on the same channel to reduce the effect that one AP may have on another.

Use non-overlapping channels (for example, 1, 6, and 11). However, the exact channel to use can only be determined after a wireless site survey.

SSID Broadcast Controls whether the SSID is broadcast. Do not broadcast the SSID (only applies to APs).

Transmit Power Indicates the transmit power (in mW) of the WLAN devices. Transmit Power applies to both the AP and the clients.

InnerWireless DAS: Contact your Johnson Controls wireless representative for the proper setting. Otherwise, set this field to the minimum setting that allows devices to communicate reliably.

Client Transmit Power

This is a Cisco Systems® brand-specific feature, which limits the transmit power from the clients.

InnerWireless DAS: Contact your Johnson Controls wireless representative for the proper setting. Otherwise set this field to Maximum.

Data Rates Defines the rate of data transfer on the WLAN. The AP automatically throttles this setting down to lower data rates in an attempt to maintain a connection.

By default, 802.11b APs operate at 1, 2, 5.5, and 11 Mbps data rates. Set the AP feature that allows it to switch between data rates automatically.

IP Address Each wireless device (including APs and wireless bridges) must have a unique IP address and can be static or dynamic.

Contact the IT department for an IP address for each device. If your AP provides IP addresses to associated devices, be sure to coordinate with the IT department to prevent duplicate IP addresses.

Encryption Provides security on the WLAN. Use WEP as a minimum level of protection.

Figure 4 provides a configuration overview. For specific procedure details, see the Appendix - Procedures section.


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Connect to the Access Point (AP) and

verify firmware version (upgrade if lowerthan specified in the Appendix).

Connect to the wireless bridge and verifyfirmware version (upgrade if lower than

specified in Appendix).

Configure the AP.Record the IP Address.See Configuring the AP.

Configure the Wireless Bridge.Record the IP address.

See Configuring the Wireless Bridge.

Log in to AP Associations Page to verifythat the Wireless Bridges are Associated

with the proper AP.See Checking Associations.

Repeat for each APassociated with the

Metasys system.

Repeat for each WirelessBridge associated with the

Metasys system.

appn

otef

low

char

t

Power up devices.Plug AP and PC into wired network.

Check Signal Quality of all associateddevices.

See Checking Signal Quality.

Ping all devices from the PC to eachwireless bridge through the AP.

Yes

Go to Troubleshooting.

Turn on continuous ping(PING -t < IP ADDRESS) from

DOS window.

Connect NAE to wireless bridge.

No

Dosignificant timeouts

occur (more than 2%of PINGs lost)?

Ping NAE from PC.

Are the devicesassociated to the

correct AP?

No

Yes

Bring NAE Web page online in Webbrowser.

Do you have goodsignal quality?

No

Yes

Can you PING the APfrom the PC?

Yes

Contact IT department. No

Dosignificant timeouts

occur (more than 2%of PINGs lost)?

No

YesDoes the NAE

appear on the APAssociations

Page?

** If Yes, see Poor Signal

Quality. If No, see NotAssociated with AP.

Figure 4: Configuration Overview


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Wireless Issues and Risks Reliability is a concern on a wireless network since the existing standard is an unlicensed band. The wireless network can change if it is not monitored and controlled. Changes in the wireless network can cause Metasys system performance to degrade, fluctuate, or toggle on and offline.

The following list illustrates some factors that can cause changes to the wireless network. The wireless network can change if:

• users bring wireless devices in and out of the building that interfere with the wireless channels being used for the Metasys system

• the physical environment is changed, such as new walls going up, the temperature where the devices are mounted exceed the operating thresholds, or adjacent tenants install their own wireless network

• wireless device configuration is modified or new firmware is added to some of the devices

• wireless bandwidth needs to be shared by more users or devices

• a rogue user attempts to create a wireless denial of service

• performance degrades or a device fails

• wireless data needs to transfer between several APs or traverse a congested wired network

• operation between different vendors’ devices causes system-wide wireless problems

Other wireless devices exist in the market place that use the same 2.4 or 5 GHz frequency bands and can cause interference to the wireless network. These devices include, but are not limited to, other 802.11 wireless LAN devices, wireless headphones, cordless telephones, cameras, and wireless audio speakers.

Competing Technologies The 2.4 and 5 GHz frequencies allow a variety of devices to operate within their spectrums including 802.11b/g (2.4 GHz) devices, 802.11a (5 GHz) devices, Bluetooth™ wireless technology (2.4 GHz) devices, and digitally modulated devices.


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802.11b and 802.11g technologies employ Direct Sequence Spread Spectrum (DSSS). This technology compensates for the noise in these bands by spreading the signal out over a wider frequency range. Maximum output power for 802.11 devices is limited to 100mW in the 2.4 GHz band. Other classes of devices in the 2.4 GHz band allow digitally modulated devices to output up to 1W. It is, therefore, important to perform a wireless site survey prior to installing a wireless network.

RECOMMENDATION: First, actively monitor the WLAN spectrum to look for increasing activity.

IMPORTANT: The nature of wireless communication allows clients to move around. Consider this when performing the site survey. Consider where people will be using their wireless devices. For example, do not place an NAE on a WLAN near a conference room where 20 people might be using wireless laptop computers.

Note: The Johnson Controls wireless representative will arrange for a site survey to be performed before installing a wireless infrastructure system.

Note: Third-party software tools are available to monitor wireless activity. One example of wireless monitoring software is Airopeek NX™ software by WildPackets, Inc. This is available at www.wildpackets.com.

Second, in order to allow these systems to coexist, specify that your wireless partner reduce the power output to a level that still allows for acceptable performance. Devices transmitting at the highest possible power level when unneeded increase the noise to other devices within this band.

Denial of Service (DOS) Attacks A wireless DOS attack occurs when a malicious user sends numerous dissociative messages to a network in an effort to degrade network performance. The malicious user attempts to send messages to client devices or to set up APs on the same channel as the Metasys wireless network.

RECOMMENDATION: Actively monitor and log malicious activity. This can lead to identification and the source of this kind of activity.


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Security Mechanisms The IEEE standards define encryption and authentication layers to secure transmissions. Table 4 describes the current security mechanisms.

Note: Only the WEP 128-bit encryption has been tested on the wireless Metasys network.

Table 4: Security Mechanisms Name Full Name Description WEP Wired Equivalent Policy Uses an encryption procedure to protect or increase the security

of a wireless transmission. Uses an encryption key to mathematically encrypt the transmitted data.

WPA Wi-Fi Protected Access Improves on the security of WEP by using improved data encryption and user authentication.

EAP Extensible Authentication Protocol

Provides a general protocol for authentication that also supports multiple authentication methods, such as token cards, Kerberos, one-time passwords, certificates, public key authentication, and smart cards.

RECOMMENDATION: Implement one of the security mechanisms from Table 4. You should maintain your equipment at the newest versions of security. Also, do the following:

• Do not broadcast SSIDs. Disable Cisco brand’s guest mode.

• Use a Wi-Fi protocol packet analyzer to look for rogue APs or clients that are not part of the wireless network.

• Change the default passwords on the access points and wireless bridges or eliminate the default account and create a new username and password.

Choosing Wireless Devices and Equipment Vendor selection is extremely important in creating a stable wireless environment. One of the main criteria to consider is wireless sensitivity. The wireless sensitivity should be –85 to –90 dBm range for 11 Mbps data rate. Lower end devices usually compromise cost by using a lower end receiver. Reduced sensitivity results in increased device disassociations from the AP, more data retries/timeout, and running at a lower data rate. The sensitivity data rate difference is 8 dBm between 11 Mbps and 1 Mbps, which means that as the signal strength decreases, the data rate also decreases to a lower level.


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Also, consider the following questions:

• Does the site IT department require a certain brand of client devices?

• Does the site already have a certain brand of APs already in place (if so, you should typically purchase client devices to match the brand of APs)?

• Will the vendor be around in 5 years to provide technical support for installed wireless infrastructure?

• Are the devices easy to set up?

• Is it easy to upgrade the firmware (which may be required to improve performance or allow for interoperability with new standards such as Wi-Fi Protected Access [WPA])?

• Does the vendor provide extra features? For example:

- Look for features like transmission of wireless power level (allows devices to send data at the lowest required power level)

- Automatic switching to less congested channels (helps where other APs and noise are using the same channel).

Vendor Interoperability As the number of vendors of WLAN equipment in the 802.11 space continues to increase, it is important to recognize that there may be compatibility issues between devices. Vendors may have a slightly different interpretation of the protocol specifications and add additional features. Additional features improve their own performance and security features, but prevent other WLAN devices from operating properly (for example, Cisco Systems Aironet® Extensions). It is important to recognize that the WLAN standard only controls the minimum feature set that needs to be supported, but vendors are free to add their own extensions.

Also, vendors may attempt to rush products to market and to push patches to fix problems or meet the standards.

RECOMMENDATION: Use only wireless products from a core set of companies. See the Appendix - Tested Equipment section in this document for a list of devices tested with the Metasys system extended architecture wireless network


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Performance Expectations On a well-designed wireless network using 802.11b protocol, you can expect performance comparable to a 10 Mbps wired network. However, since users can roam in a wireless system, it is possible that a network device could become overloaded at any time.

802.11g/a systems can provide additional performance with higher data rates; however, the wireless Metasys network has only been tested with 802.11b. See the Appendix - Tested Equipment section in this document for a list of devices tested with the Metasys system extended architecture wireless network

Metasys System Performance Using the wireless 802.11b Metasys network, you can have the same number of NAEs on a Metasys network on a comparable 10 Mbps (10 base-t) wired system. You can also expect the same performance as if the NAE were on a wired network.

Note: Due to wireless bandwidth requirements, we recommended that you place the Application Data Server (ADS) or the Extended Data Server (ADX) on the wired network, and the computers running the Web browser software for accessing the Metasys User Interface (UI) on the wireless network.

For more information about the Metasys system extended architecture, refer to the Metasys System Extended Architecture Overview Technical Bulletin (LIT-1201527).


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Appendix - Procedures This section provides the procedures a person trained in this field must perform to set up a wireless network. Do not try to configure the wireless network without the input of the customer IT department, a wireless solutions company, and/or other wireless resources.

Note: The procedures in this document are examples using equipment from the Appendix - Tested Equipment section in this document.

IMPORTANT: Change the default passwords of the APs and wireless bridge devices. Failure to change the default password allows unauthorized users full access to your system and system settings.

Installing the AP To install the AP, refer to the manufacturer’s instructions. Once the AP is installed, proceed to the Configuring the AP section of this document.

Configuring the AP To configure the AP:

Note: You can configure the AP using a Web browser, Telnet session, or a direct serial connection (depending upon the manufacturer). These instructions show how to configure the Cisco 1200 AP using a Web browser.

1. Type the IP address of the AP in the Address bar of the browser and log on using the manufacturer supplied password. The Cisco 1200 Access Point Home screen appears (Figure 5).


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Figure 5: Cisco 1200 Access Point Home Screen 2. Click System Software. The System Software screen appears

(Figure 6).


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Figure 6: System Software Screen 3. Verify that the System Software Version matches the system

software version (or later) listed in Table 10.

If the System Software Version does not match, download and upgrade the software according to the manufacturer’s instructions.

4. Click Network Interfaces > IP Address. The IP Address Screen Appears (Figure 7).


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Figure 7: IP Address Screen 5. Set the fields according to your IT department. Click Apply.

Note: Set Static or DHCP according to your IT specifications.

6. Click Network Interfaces > Radio0-802.11B and select the Settings tab. The Radio0.802.11B Settings screen appears (Figure 8).


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Figure 8: Radio0.802.11B Settings Screen 7. Set the fields according to Table 5 and click Apply.

Table 5: Radio0.802.11B Settings Field Setting Enable Radio Enable Transmitter Power Wireless Infrastructure System: See Note.

Otherwise, set to the minimum setting that allows devices to communicate reliably.

Limit Client Power Wireless Infrastructure System: See Note. Otherwise, set to the minimum setting that allows devices to communicate reliably.

Receive Antenna Wireless Infrastructure System: See Note. Otherwise, set field to Diversity.

Transmit Antenna Wireless Infrastructure System: See Note. Otherwise, set to Diversity.

Aironet Extensions Enable (only set to Enable if you are using all Cisco Systems devices and other 802.11 devices, which support the Cisco Aironet extensions; otherwise, set to Disable)

Note: If you are using a wireless infrastructure system by Johnson Controls, your Johnson Controls wireless representative provides this setting.


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8. Click Security > SSID Manager. The SSID Manager screen appears (Figure 9).

Figure 9: SSID Manager Screen 9. Set the SSID for this installation and click Apply.

10. Click Security > Encryption Manager. The Encryption Manager screen appears (Figure 10).


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Figure 10: Encryption Manager Screen 11. Set the fields according to Table 6 and click Apply.

Table 6: Encryption Manager Settings Field Setting WEP Encryption Enabled and Mandatory Encryption Key 1 Transmit Key Enabled Encryption Key* Type in a 26-character string Key Size 128 bit * The Encryption Key is used by all wireless clients on the system that access

this AP and should be provided by the IT department. Store Encryption Key in a secure location.

Note: The AP can use other types of encryption. Refer to the AP technical literature for more details. The clients must use the same type of encryption used by the AP.

12. Review your settings and close the browser.


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Installing the Wireless Bridge To install the wireless bridge, refer to the manufacturer’s instructions. Once the wireless bridge is installed, proceed to the Configuring the Wireless Bridge section of this document.

Configuring the Wireless Bridge To configure the wireless bridge:

Note: These instructions show how to configure the Cisco 350 wireless bridge when directly connected and using a Web browser. Refer to the manufacturer’s instructions for details.

Note: Cisco System, Inc. reports that they are changing the user interface of the Cisco 350 wireless bridge. Your screens may appear differently.

1. Type the IP address of the wireless bridge in the Address bar of the browser. The Cisco 350 wireless bridge page appears (Figure 11).

Figure 11: Cisco 350 Wireless Bridge Screen - Showing System Software Version 2. Verify that the System Software Version matches the system

software version listed in Table 10.


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If the System Software Version does not match, download and upgrade the software according to the manufacturer’s instructions.

3. Verify that the screen reads Allow Config Changes in upper left-hand corner of the screen.

Note: If it reads Disallow Config Changes, click on Disallow Config Changes to toggle the mode to Allow Config Changes.

4. Click Configuration > Identity. The Identity screen appears (Figure 12).

Figure 12: Identity Screen 5. Set the IP related fields according to your IT specifications.

6. Click Configuration > Radio. The Radio screen appears (Figure 13).


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Figure 13: Radio Screen 7. Set the Service Set Identification (SSID) to be the same as the AP

you are going to access.

8. Click Privacy configuration. The Privacy Configuration screen appears (Figure 14).


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Figure 14: Privacy Configuration Screen 9. Set the Key number for transmit field to match the Encryption

Key of the AP (see Figure 10).

10. Click Home and review your settings.

11. Close the browser.

Configuring Wireless Clients To configure wireless clients, refer to the literature provided with your client device.

Wireless clients (wireless LAN cards and other devices) must use the same SSID and encryption type as the AP to communicate with the AP.


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Checking Associations You can check associations from the AP or from the wireless bridge. For example, if you check the AP Association page and see that your wireless bridge is not associated to that AP, you can check the wireless bridge’s Association page to see if it is associated with a different AP.

AP To check the associations of devices connected through the AP:

1. Type the IP address of the AP in the Address bar of the browser and log on to the AP. The Cisco 1200 AP page appears (Figure 5).

2. Click Association. The Association screen appears (Figure 15) and shows all devices associated with the AP.

All client devices on the wireless bridge are listed in the Device Type column as WGB-Client, including an NAE communicating through this AP. Once the wireless bridge appears on the Associations page, the IP address of the NAE also appears on the page.

Note: If the IP address of a device is 0.0.0.0, the device has been disconnected, the IP address is not set up properly, or the device needs to be investigated.

Refer to the manufacturer’s instructions for more information regarding the Associations page.


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Figure 15: AP Association Screen

Wireless Bridge To check the associations through the wireless bridge:

1. Type the address of the wireless bridge in the Address bar of the browser. The Cisco 350 wireless bridge page appears (Figure 11).

2. Click Association. The Association screen appears (Figure 16).


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Figure 16: Wireless Bridge Association Screen 3. Click All. The Association Tables screen appears (Figure 17).


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Figure 17: Wireless Bridge Association Table Entries Screen Note: The AP to which this wireless bridge is associated is labeled Prnt (for parent) in the Type column. Me refers to the wireless bridge and Clnt refers to any device directly connected to the wireless bridge (including the NAE).

Note: Refer to the manufacturer’s instruction for more detail regarding the wireless bridge.

Checking Signal Quality You can check the signal quality of the wireless bridge in two ways, through the AP or through the wireless bridge itself.

AP To check the signal quality through the AP:

Note: You can check the signal quality of any device associated to the AP.

1. Type the IP address of the AP in the Address bar of the browser and log on to the AP. The Cisco 1200 AP page appears (Figure 5).

2. Click Association. The Association screen appears (Figure 15).


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3. Click on the MAC address of the device you want to check. The Statistics Tab of the Association screen appears (Figure 18).

Figure 18: Statistics Tab of the Association Screen 4. Compare your results to Table 7.

Table 7: Signal Levels Parameter Acceptable* Range Signal Strength Above 50% or between –20 and –80 dBm Signal Quality Above 50% * If either the Signal Strength or the Signal Quality is not acceptable, see the

Initial Installation Troubleshooting Flowchart (Poor Signal Quality) (Figure 21).

5. Click the Back button and click another MAC Address or close the browser.

Wireless Bridge To check the signal quality of the wireless bridge through the wireless bridge:

1. Type the IP address of the wireless bridge in the Address bar of the browser. The Cisco 350 Wireless Bridge page appears (Figure 11).


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2. Click Diagnostics > Linktests. The Linktests screen appears (Figure 19).

Figure 19: Linktests Screen 3. Click Run a signal strength test. The Signal Levels screen appears

(Figure 20).


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Figure 20: Signal Levels Screen 4. Compare your results to Table 8.

Table 8: Signal Levels Parameter Acceptable* Range Signal Strength Above 50% Signal Quality Above 50% * If either the Signal Strength or the Signal Quality is not acceptable, see the

Initial Installation Troubleshooting Flowchart (Poor Signal Quality) (Figure 21).

5. Close the browser.


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Appendix - Troubleshooting

Trou

bles

hoot

_flo

wch

art

Not Associated with AP

Check devices for error LEDs and verify power to device.

Check for signal strength, signal quality, and power fluctuations

throughout the day.

Check to see if the Wireless Bridge is associated with another

AP.See Checking Associations.

Verify settings of the Wireless Bridges and APs including SSID, IP, WEP,

Diversity, antenna connection, firmware version, and so on)

Move wireless device (or external antenna, if applicable) closer to the

AP.

No

Yes

Are you using a wireless infrastructure

system?

Do you have multiple APs?

Yes

Do not modify parameters with which you are unfamiliar.

Contact your Johnson Controlswireless representative.

Contact IT resource.

Poor signal qualitySignificant data retries

(more than 2% of PINGs are lost)

Check AP and Wireless Bridge event logs. Look for abnormal behavior (such

as disassociated devices).See Activity Logs.

Did this resolve the problem?

Look for sources of interference (using a spectrum analyzer and an

802.11 packet analyzer)

No

Yes

You may have a problem in your wireless network design or may be

experiencing interference.

No

Are Signal Strength and Signal Quality

within acceptablelimits?

No

Yes

Adjust the antenna.

Figure 21: Initial Installation Troubleshooting Flowchart


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Problems and Recommendations Table 9: General Troubleshooting Conditions Condition Suggested Actions Clients No Longer Associated to AP

1. Check the link light on client device. 2. Cycle the power on the device. 3. See Figure 21: Initial Installation Troubleshooting Flowchart. 4. Verify if a new version of the firmware is available for the wireless device.

Poor Performance See Figure 21: Initial Installation Troubleshooting Flowchart. 1. Check the bandwidth loading on the wired and wireless segments. 2. Verify if a new version of firmware is available for the wireless device. 3. If you have multiple APs, verify that all APs within close proximity are set

up to use different channels. 4. Verify if a new version of the firmware is available for the wireless device.

Sporadic Performance Sporadic performance typically indicates that there is a source of interference and requires spectrum analysis. See Wireless Spectrum Interference. 1. Monitor bandwidth loading on wired/wireless networks. 2. Verify if a new version of the firmware is available for the wireless device.

For more information, refer to the technical literature or technical support provided by the vendor of your wireless equipment.

Interference - Wireless Spectrum Sweep Noise or interference on the channel used by the WLAN AP and client can cause issues on the wireless network ranging from periodic performance degradation to completely overpowering the wireless signal used by the AP and clients. If noise overpowers the channel, devices may not be able to communicate. This noise could come from something as simple as a microwave oven, a malfunctioning switching power supply, or WLAN devices in your own or adjacent buildings.

RECOMMENDATION: To overcome some interference issues, perform a frequency sweep of the spectrum you want to use before installing the wireless system. Someone trained in the usage of a Radio Frequency (RF) spectrum analyzer can perform this sweep. This precaution is necessary to determine the level of noise that appears across the wireless spectrum. This sweep needs to be performed at various times of the day and week to determine the best channel to use. It may also be possible to trace and eliminate the source of the noise. Additionally, periodic sweeps should be performed and compared to the initial baseline. Any differences should then be analyzed and accounted for. Even if other signals are present in the same channel, they may not necessarily cause a problem.

Also, avoid using APs on the same channel. Use APs on non-overlapping channels (for example, Channels 1, 6, 11). This precaution reduces the effect that one AP may have on another.


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Wireless Spectrum Interference WLANs using the same channel can reduce the performance of a wireless network. It is difficult to determine the extent of the interference by relying solely upon a spectrum analyzer. You can use a WLAN packet analyzer to identify all of the packets being transmitted on a specific channel and where the packets are originating. With this tool, you can also determine packet transmit times, number of retries, signal strength for each packet, and types of packets (that is, if the majority of packets are coming from the Metasys devices or from adjacent wireless networks or devices).

RECOMMENDATION: Monitor the WLAN periodically using a packet analyzer.

Note: AP vendors (Cisco Systems for instance) may provide software tools with their AP to monitor the wireless spectrum. Refer to manufacturer’s instructions for details.

Bandwidth Limitations The 802.11b protocol is limited to a maximum of 11 Mbps and 802.11a/g are limited to a maximum of 54 Mbps according to the WLAN standard. This bandwidth can vary, depending on both the signal strength and the signal quality. Design your system for the maximum data rate possible. Performance may degrade at lower data rates. Performance also can be affected when the data bandwidth needs to be shared by other high consumers of the bandwidth. For example, if a user is using a wireless laptop to transfer large files or a Voice-over-IP (VOIP) phone and these devices are connected to the same AP as the Metasys system, the performance of the Metasys system can be greatly degraded.

RECOMMENDATIONS:

• Monitor the wireless bandwidth use regularly and at various times throughout the day. If bandwidth becomes excessive, add additional bandwidth (by adding APs on additional channels) or throttle the devices causing the load on the wireless network.

• Some AP manufacturers (Cisco Systems, for instance) allow for a prioritized Virtual LAN (VLAN). If possible, place the Metasys system on a high priority VLAN.

• Ensure that the AP is on a smart switch or router that only allows wireless data traffic.

• Identify and, if possible, throttle major bandwidth users.


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AP Overview Summary The Radio0-802.11B Status tab (Figure 22) provides a summary of the status of the AP’s performance and configuration. This tab also provides statistical data, including:

• packets sent and received

• time online

• power settings (transmit and receive)

Figure 22: Radio0-802.11B Status Tab Screen

Activity Logs The activity logs in the AP (Event Log screen, Figure 23) and wireless bridge (Logs screen, Figure 24) provide information regarding the activity of the device. You can look at the activity logs if you suspect there are issues with the wireless LAN, including:

• devices not associating with the correct AP

• devices disassociating from the AP

• too many retries


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We recommend that you reset the activity logs occasionally. Refer to the manufacturer’s instructions provided with the AP or wireless bridge for details.

Figure 23: AP Event Log Screen


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Figure 24: Wireless Bridge Logs Screen


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Figure 25: Wireless Bridge Log and Alarm History Screen

Outdoor AP or Bridge Configuration Outdoor APs and antennas may be subject to environmental factors including heat, cold, humidity, corrosion, lightning, vibration, new sources of wireless interference, antenna placement issues, rain, or wind. Carefully consider all of these factors when creating an outdoor wireless network.

Servicing Equipment We recommend that you periodically check the wireless equipment environment to ensure that the surroundings have not been altered.


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Appendix - Tested Equipment Hardware and Software Table 10: Tested Equipment Brand Name Model Firmware Version/ Revision Number AP Cisco Systems Aironet 1100 Series 12.2(13)JA, or later Cisco Systems Aironet 1200 Series 12.2(13)JA, or later Cisco Systems Aironet 1400 Series 12.2(13)JA, or later Wireless Bridge Cisco Systems 350 Workgroup Bridge WGB350 V8.84, or later Cisco Systems 352 Workgroup Bridge WGB352 V8.84, or later Wireless Card Cisco Systems 350 Wireless LAN Client Adapter 5.30.17, or later

Packet Analyzers Packet analyzers are used to monitor wireless network traffic and perform site surveys. The following list includes two vendors that provide this type of software.

• WildPackets, Inc.

www.wildpackets.com

• Analyser Sales Ltd.

http://www.asl-netasyst.co.uk/

Controls Group 507 E. Michigan Street P.O. Box 423 www.johnsoncontrols.comMilwaukee, WI 53202 Published in U.S.A.

Documents

Metasys® System Extended Architecture Application Note