Fortress Technologies BreadCrumb Wireless Network manual Device power To Device power Distance

Chapter 4. Deployment Considerations

Unobstructed LOS is not necessary from every BreadCrumb device and wireless client to every other BreadCrumb device and wireless client. However, each device must have unobstructed LOS to the previous and subsequent device.

Distance

Many factors determine acceptable distances between BreadCrumb devices when deploying a BCWN.

If many devices are placed too closely together, it is possible that interference will degrade the performance of the system.

Devices that are placed too far away or in RF "shadows" may experience total loss of connection.

Device power is important in determining distances over which the device will be effective.

The following table can be used as a guide to determine best-case distances between devices with regard to their power:

	Device (power)	To Device (power)	Distance	* 1
BreadCrumb device (200mW)		BreadCrumb device (200mW)	Up to 5km (3.1 miles)
with external antenna		with external antenna
BreadCrumb device (200mW)		BreadCrumb device (1W)	Up to 10km (6.2 miles)
with external antenna
BreadCrumb device (1W)		BreadCrumb device (1W)	Up to 15km (9.3 miles)
Notes:
a. These distances are representative of optimal deployment settings:
•	Optimal antenna selection
• Clear, unobstructed LOS between devices
• Absence of other RF interference
•	Full battery power
•	Clear weather

Table 4-1. Best-Case Distances by Radio Power

Tip: It is recommended when deploying a BCWN that you choose initial distances between devices that are half the distance as quoted in Table 4-1.

When placing a BreadCrumb device, check the connection status to the nearest available device using either the BreadCrumb device’s status LED (described in Appendix A), or BCAdmin (described in Chapter 5). If the connection is poor or non-existent, attempt to relocate the BreadCrumb device closer to another device until an acceptable connection is obtained. If a poor connection or no connection is made at even relatively close distances, you should refer to Chapter 7.

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