}EEE Communications $agazine • Januar 2--~56 -j~L-~Ö-’P-~P$2-.-- 2--~ }EEE
1
T? ?m public saet?
land mobile radio ??s
o w?lss sys?ms usd by
ublc sa?y ag?c?s o?
cood?a?g ?ams ad
?ovd?g a?d m?g?cy
?sos?
? UBLIC SFETY
INT?DUTIN
Di?erences in market orces, requirements,
spectrum polic, and other actors have driven
toda’s public saet land mobile radio
j
(L$R)
and commercial wireless technologies along dis-
parate evolutionar paths. These di?erences
have had a dramatic inluence on the speed with
which public saet and commercial wireless
technologies have evolved and are being
deploed. Toda, public saet wireless networks
worldwide are in the earl stages o migrating to
narrowband, circuit-switched digital voice tech-
nologies with limited support o low-speed data
services. }n contrast, commercial wireless net-
works toda are now transitioning to spectrall?
e?icient, broadband, packet-switched air inter-
aces supporting a wide variet o real-time and
non-real-time broadband multimedia applica-
tions.
Public saet wireless networks are beginning
to incorporate commercial wireless data tech-
nologies, a trend that is likel to continue to gain
momentum. Underling this trend is one unda-
mental act: the public saet user communit is
two orders o magnitude smaller than the com-
mercial user base. As a result, R&D investments
in commercial wireless technologies dwar those
made in public saet wireless technologies. }n
addition, the large size o the commercial wire-
less market osters greater levels o competition
between vendors o network inrastructure, user
devices, and applications. Use o commercial
technologies toda can provide a wide spectrum
o beneits to irst responders, including low cost
devices in a variet o orm actors, signiicant
increases in user data rates, and a wide spectrum
o new services (e.g., multimedia messaging,
high-speed data services, and video).
}n this article, we eplore and compare the
orces that have shaped public saet and com-
mercial wireless networks. We eamine some o?
the unique public saet user requirements that
initiall set public saet wireless networks on an
independent evolutionar path. $an o the ser-
vices and eatures once considered unique to
public saet users no longer mandate the
deploment o networks emploing special-pur-
pose public saet radio access technologies.
}nstead, man o these eatures ma be imple -
mented at the application laer, taking advan-
tage o the core and Radio Access Network
eatures that are being deploed in commercial
LG wireless networks to support real-time }P-
based multimedia services.
We propose uni?ing public saet communi-
cations resources: bridging commercial wireless
and L$R access inrastructure using a common
}P-based core network emploing service-intelli-
gent session control to provide local, regional, or
national service. We term this common core net-
work and its associated heterogeneous access
networks a $obile Responder Communication
Network ($RCN). $RCNs will help urther
accelerate the rate at which public saet users
can beneit rom commercial wireless access
technologies while preserving legac investments
in public saet L$R technologies.
? ?x TING MBI? ? SPND?
? MMUNIxTIN NTW?KS F?
PUBI? SxFT?
Public saet wireless networks have traditionall?
been owned and managed b individual agencies
(e.g., ire, law enorcement, emergenc medical
services, etc.) as stove-piped networks at the ed -
eral, state or local government levels. While
these networks are designed to support mission-
Kr?hn B??hnrn, Kenneh C. B?k, Th?? . Ch, Tew?k L. D??, n J?eph H. Kng, Be?
Lb, L?en Tehn?ge?
x BSTxT
This article proposes a paradigm shit rom
the prevailing public saet model o disparate,
agenc-owned and -operated Land $obile Radio
networks to $obile Responder Communication
Networks ($RCNs) that are created b uni?ing
communications resources and are shared across
cooperating public saet agencies to provide
local, regional, or national service. $RCNs use
a common }P-based core network emploing ser-
vice-intelligent session control to bridge net-
works based on L$R and commercial wireless
access technologies, thus allowing the support o?
emerging }P-based multimedia services, high
data rate access, and mission-critical tactical
group voice and interoperable communications
during emergenc responses.
Moil ?pond? o?unicaion
N?o? o Pulic Sa?y
B??H?D? ?YUT ?()()5 7:5 M Pge 56