COMMISSION 
AGENDA MEMORANDUM                        Item No.          8c 
ACTION ITEM                            Date of Meeting    September 27, 2022 

DATE :     September 16, 2022 
TO:        Stephen P. Metruck, Executive Director 
FROM:    Mike Tasker, Director, Aviation Maintenance 
Krista Sadler, Director Technology Delivery 
SUBJECT:  Radio Microwave Redundancy Loop (CIP #C801263) 
Amount of this request:               $2,500,000 
Total estimated project cost:          $2,500,000 
ACTION REQUESTED 
Request Commission authorization for the Executive Director to 1) proceed with the Radio
Microwave Redundancy Loop project; 2) execute contract(s) for hardware, software, and
services; and 3) execute up to three leases for Port capacity on Microwave Towers for a total
project cost not to exceed $2,500,000 and 5-year lease costs estimated $840,000. 
EXECUTIVE SUMMARY 
This project will add up to three Radio Microwave sites to create a loop topology between tower
sites to ensure connectivity in the event of an incident that takes a tower out of commission.
With the tower loop design, each site will have multiple pathways to get to the prime site at
Seattle-Tacoma International Airport (SEA). In addition, the project will activate a backup, virtual
prime site to protect against issues with the SEA prime site. Capital costs for the buildout of the
three new sites and the activation of the backup site are $2,500,000. Lease costs for space on
new tower sites or additional capacity on current sites is estimated at $840,000 over five years. 
The Port of Seattle operates its own mixed-mode radio network that is a vital communication
system. It includes over 1900 radios and dispatch consoles for the Port Public Safety
departments, Aviation Operations, Aviation and Maritime Maintenance, Aviation and Maritime
Security and Emergency Preparedness teams who rely heavily on the radio system for day-to-day
operations and incident response. It is also the critical communication link for mutual aid
responders within adjacent jurisdictions who will come into the Port’s radio coverage area to aid 
during emergencies. 
Our current towers operate serially to send radio communications to the Prime site at SEA. If a
single link is lost, at least one site and possibly more, depending on where the break is, will lose

Template revised January 10, 2019.

             COMMISSION AGENDA – Action Item No. 8c                                   Page 2 of 4 
Meeting Date: September 27, 2022 
connectivity. This will reduce our radio coverage area and potentially leave radio users in the field
unable to communicate with dispatchers and other radio users until the link is restored. 
JUSTIFICATION 
With the current serial tower design, if there is a tower taken offline for any reason, all radio
communication is down for radios served by that site or sites beyond. While there are work
arounds for planned outages, they require significant coordination. A full transition to a backup
system, could take several days. In addition, the first mitigation for a north end outage is to utilize
the City of Seattle radio network. If they are also experiencing outages from similar threats, the
outages could be much longer. 
Diversity in Contracting 
Project staff will work with the Diversity in Contracting Department to determine if a direct
women-and-minority-owned business enterprise (WMBE) aspirational goal should be assigned.
It is expected that opportunities will be limited for this proprietary system. 
DETAILS 
Scope of Work 
(1)   Procurement of equipment and services from Motorola, our radio vendor 
(2)   Design and installation of new sites 
(3)   Testing and activation of the virtual prime site for further redundancy 
Schedule 
Commission authorization                      2022 Quarter 3 
Contract Completion                           2022 Quarter 4 
Design and Site Identification Completion        2023 Quarter 2 
In-use date                                       2024 Quarter 1 
Cost Breakdown                                     This Request           Total Project 
Equipment and Implementation Services                 $2,100,000            $2,100,000 
Port Labor                                                  $400,000               $400,000 
Total                                                         $2,500,000              $2,500,000 




Template revised June 27, 2019 (Diversity in Contracting).

             COMMISSION AGENDA – Action Item No. 8c                                   Page 3 of 4 
Meeting Date: September 27, 2022 
ALTERNATIVES AND IMPLICATIONS CONSIDERED 
Alternative 1 – Create redundancy through duplicative Wide Area Network Connectivity between
towers 
Cost Implications: $300,000 Capital; $200,000 Five-year Recurring Cost 
Pros: 
(1)   Lower cost alternative 
Cons: 
(1)   This alternative requires a manual failover that could take 1-2 days for activation. 
This is not the recommended alternative. 
Alternative 2 – Build Radio System redundancy by creating a loop topology with additional tower
sites 
Cost Implications: $2,500,000 Capital; $900,000 Five-year Recurring Cost 
Pros: 
(1)   An entire site can be removed from the loop and the other sites would remain
connected to the SEA prime site, resulting in no loss of radio communication
capabilities. 
(2)   If the SEA prime site goes down, we will have full redundancy with our virtual prime
site. 
Cons: 
(1)   Higher cost alternative 
This is the recommended alternative. 
FINANCIAL IMPLICATIONS 
Cost Estimate/Authorization Summary              Capital        Expense           Total 
COST ESTIMATE 
Original estimate                                 $2,500,000               $0      $2,500,000 
AUTHORIZATION 
Previous authorizations                                   $0                0               $0 
Current request for authorization                $2,500,000                0      $2,500,000 
Total authorizations, including this request       $2,500,000                0      $2,500,000 
Remaining amount to be authorized                    $0             $0             $0 
Annual Budget Status and Source of Funds 
This project was included in the 2022-2026 Corporate capital budget and plan of finance for
$2,500,000 in CIP# C801263. The project will be funded with 82.1% Airport Development Fund
and $17.9% General Fund. 

Template revised June 27, 2019 (Diversity in Contracting).

             COMMISSION AGENDA – Action Item No. 8c                                   Page 4 of 4 
Meeting Date: September 27, 2022 

Financial Analysis and Summary 
Project cost for analysis              $2,500,000 
Business Unit (BU)                  Administrative for allocation to Aviation 
Effect on business performance     NOI after depreciation will increase due to inclusion of
(NOI after depreciation)             capital (and operating) costs in airline rate base. 
IRR/NPV (if relevant)                Less than $0.01 in 2024 
CPE Impact 
Future Revenues and Expenses (Total cost of ownership) 
The Port will need up to three new site leases for microwave tower space at an estimated cost of 
$144,000 annually. In addition, new capacity may be required at existing microwave towers that
could increase annual costs by $24,000 for a total annual cost of $168,000 and five-year costs of
$840,000. Annual costs will be included in the Aviation Maintenance Operating Budget. 
ATTACHMENTS TO THIS REQUEST 
None 
PREVIOUS COMMISSION ACTIONS OR BRIEFINGS 
None 









Template revised June 27, 2019 (Diversity in Contracting).