User's Manual
Table Of Contents
- Cambium
- PMP 450 Planning Guide
- Accuracy
- Copyrights
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- Restrictions
- License Agreements
- High Risk Materials
- Safety and regulatory information
- Contents
- List of Figures
- List of Tables
- About This Planning Guide
- PMP support website: http://www.cambiumnetworks.com/support
- Cambium main website: http://www.cambiumnetworks.com/
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- Address:
- Chapter 1: Planning considerations
- Regulatory planning
- Network migration planning
- Site planning
- Link planning
- Analyzing the RF Environment
- Selecting Sites for Network Elements
- Diagramming Network Layouts
- Grounding and lightning protection
- Configuration options for TDD synchronization
- Data network planning
- Security planning
- Isolating APs from the Internet
- Managing module access by passwords
- Filtering protocols and ports
- Port Lockdown
- Isolating SMs
- Filtering management through Ethernet
- Allowing management from only specified IP addresses
- Configuring management IP by DHCP
- Planning for airlink security
- Planning for RF Telnet Access Control
- Forwarding Downlink PPPoE PADI packets
- Planning for RADIUS integration
- Planning for SNMP security
- Ordering components
- Chapter 2: Legal information
- Cambium Networks end user license agreement
- Acceptance of this agreement
- Definitions
- Grant of license
- Conditions of use
- Title and restrictions
- Confidentiality
- Right to use Cambium’s name
- Transfer
- Updates
- Maintenance
- Disclaimer
- Limitation of liability
- U.S. government
- Term of license
- Governing law
- Assignment
- Survival of provisions
- Entire agreement
- Third party software
- Hardware warranty
- Limit of liability
- Cambium Networks end user license agreement
- Chapter 3: Reference information
PMP 450 Planning Guide
Figure 28 One unsynchronized AP in cluster resulting in self-interference
The result is self-interference. In this scenario, the self-interference can be avoided only by synchronizing the TDD
transmit cycles of all APs that operate in the same frequency band.
An AP that is isolated by at least 5 miles (8 km) from any other equipment can generate and pass sync pulse without
GPS timing and not risk that interference will result from the generated sync. In any other type of link, sync should
be derived from GPS timing.
Advantage of GPS synchronization
Although the embedded timing generation capability of the AP keeps a precise clock (configuration parameter Sync
Input set to Generate Sync Signal), no trigger exists to start the clock at the same moment in each AP of a cluster.
So, the individual AP can synchronize communications between itself and registered SMs, but cannot synchronize
itself with other modules, except by GPS timing (shown in Figure 29).
Figure 29 GPS timing throughout the network
Time
Time
pmp-0047 (March 2014)
1-117