MOTOROLA CANOPY APPLICATION NOTE: REMOTE ACCESS POINT Issue 1
TABLE OF CONTENTS Introduction...1 Configuration...1 Deployment...2 Antenna Characteristics...5 i
The information in this publication is subject to change without notice. Motorola shall not be liable for technical or editorial errors or omissions nor for any damages resulting from the use of this material. Each configuration tested or described many or may not be the only available solution. This test is not a determination of product quality or correctness, nor does it ensure compliance with any federal, state or local requirements. Motorola does not warrant products other than its own strictly as stated in Motorola s product warranties. MOTOROLA and the Stylized M Logo are registered in the US Patent & Trademark Office. Canopy is a trademark of Motorola, Inc. All other product or service names are the property of their respective owners. Motorola, Inc. 2003. iv
Introduction Remote Access Point (Remote AP) allows for cost effective expansion of certain geographical areas in a Wireless ISP network. In a Line of Site (LOS) environment, it is not always possible to provide adequate service to every potential customer from a standard AP cluster on a tower. Customers may be located in a valley, have foliage issues, or blocked by buildings. Remote AP allows a Canopy Access Point Module to be deployed at location that has good service to a Subscriber Module that has favorable line of site to other subscribers in the immediate vicinity. The Remote AP is run in a cross-band mode to reduce interference. The Subscriber Module at the Remote AP location will pull down bandwidth from one frequency band, and redistribute the bandwidth via the AP to local subscribers using a different frequency band. The Remote AP feature is supported with FPGA versions of 0429 and up, and software versions greater than or equal to 4.0. The Remote AP supports up to 200 Subscriber Modules. Each hop (additional daisy-chained Remote AP) adds 20mSecs of latency round trip. This document provides an overview of the Remote Access Point feature and attempts to answer the majority of questions regarding the feature. It should be noted that this document is meant to provide information on how the standard Canopy radio products available today can be specially configured into a Remote AP configuration. In the context of this document, a Canopy Remote AP is not a new product offering by Motorola, rather a recommended deployment of existing Canopy radio products to meet a specific need. Configuration All Canopy radios support the Remote AP functionality. The Backhaul Slave (BHS) and the SM can reliably pass the sync pulse and the Backhaul Master (BHM) and AP modules receive this timing pulse. The sync connection is made with a cable connecting pins 1 and 6 of the RJ-11 timing ports of the two modules. Set the Sync Input parameter on the AP or BHM Configuration web page to Sync to Received Signal (Timing Port). Set the SM or BHS Configuration page Frame Timing Pulse Gated to Enable (if the SM is out of sync don t propagate the frame timing pulse). This prevents the SM/BHS from propagating erroneous sync pulses in the event of the SM/BHS losing its sync, thus preventing potential interference. 1
Cross-band frequencies must be used for deployment of Remote AP to keep interference levels acceptable. The following table depicts the recommended radio configurations. AP Cluster SMs Serviced by AP Cluster SM at the Remote AP Location AP at the Remote AP Location SMs Serviced by Remote AP 5.7 GHz 5.7 GHz 5.7 GHz 5.2 GHz 5.2 GHz 5.2 GHz 5.2 GHz 5.2 GHz 5.7 GHz 5.7 GHz Deployment The SM Configuration web page adds a Frame Timing Pulse Gated option that can be enabled or disabled. This adds the ability to stop transmitting the sync pulse from the SM to the Remote AP if the SM itself does not have accurate timing. This helps reduce interference in a Canopy network during the failure condition. The sync cable mentioned in this document is the standard timing sync cable referenced in the Canopy user manuals. The following figure depicts a Remote AP deployment within the coverage area of one Canopy AP cluster. The AP cluster in this case is using 5.7 GHz APs. The SMs that act as the data/sync feed in the Remote AP areas are using 5.7 GHz, and the APs in the Remote AP area are using 5.2 GHz. SMs that are serviced by the Remote AP use 5.2 GHz.
The Remote AP can be (1) tied to an SM that provides service to an end user or (2) tied to an SM that acts only as a relay. The GPS ports of the AP/SM units at the Remote AP are tied together. The SM then passes sync information to the AP and the AP provides expanded coverage with minimal interference. The following diagram represents a Remote AP configuration where the SM services a customer premises as well as passing data and sync for the Remote AP.
The following diagram represents a Remote AP configuration where the SM merely passes data and sync for the Remote AP. The coupler that is shown in the diagram is straight RJ-45 female-female.
Antenna Characteristics The following diagram denotes the antenna characteristics for an AP module that uses an internal patch antenna. This can prove helpful in the context of Remote AP when trying to determine where to place the Remote AP radio to service the maximum number of users, while incurring minimal interference. The blue line represents elevation and the red line represent azimuth. 120 30 dbm 20 dbm 60 150 10 dbm 0 dbm 30-10 dbm 180 0 210 330 240 270 300