Transcript Mobile Interference 071111

The Rebirth of LMR
A Presentation for
the Radio Club of America
100th Anniversary Symposium,
November 21, 2009
Presented by Peter Moncure, VP RadioSoft
8900 Dick’s Hill Parkway
Toccoa, GA 30577
[email protected]
In this presentation, I will:
Describe NXDN
Discuss its latest advancements
Explore the possibilities for local radio
shops of true IP-based LMR
Suggest strategies
What is NXDN?
From Wikipedia:
“NXDN is a Common Air Interface (CAI) technical
protocol for mobile communications. It was developed
jointly by Icom and Kenwood. A NXDN Forum was
formed in order to promote the NXDN protocol in North
and South America.”
There are currently eleven members, among which are
Daniels, Icom, Kenwood, Ritron, Trident and a software
provider, Etherstack.
NXDN is implemented by Icom in their IDAS system
and by Kenwood as NEXEDGE.
What is NXDN?
Developed from Amateur Radio’s D-Star
Bitrate (DV mode) improved from 2.4 kbps to 4.8 kbps
Underlying IP connection protocol
Allows simultaneous digitized voice and data (950 bps)
Image courtesy Icom
What is NXDN?
The digital NXDN can
be either 12.5 kHz or
6.25 kHz wide.
Two NXDN 6.25 kHz
systems can fit within
one 12.5 kHz channel.
Image courtesy Icom
Note: in this example, the frequency centers are 3.125 kHz
offset from FCC designated channel center frequency
What is NXDN?
Channels can be
allocated as voice/voice,
voice/data, or data/data.
NXDN also supports
mixed analog FM and
digital NXDN equipment
and direct radio-to-radio
communications.
Systems may be
gradually migrated to
digital narrowband.
Image courtesy Icom
What is NXDN?
4-level frequency-shift
keying (FSK) modulation.
Digital audio uses the
AMBE+2 vocoder.
Better weak-signal
voice than analog FM.
Has wider range and
slightly better multipath
than analog FM
Data transmission bit
rate 4.8 kbps.
Image courtesy Icom
What is NXDN?
Technical Characteristics
The following FCC emissions apply to NXDN transmissions:
8K30F1E 12.5 kHz single channel digital voice
8K30F1D 12.5 kHz single channel digital data
8K30F1W 12.5 kHz single channel digital voice and data
4K00F1E 6.25 kHz single channel digital voice
4K00F1D 6.25 kHz single channel digital data
4K00F1W 6.25 kHz single channel digital voice and data
4K00F2D 6.25 kHz single channel analog CW ID
The author has personally observed greater than 75 dB isolation
from two adjacent NDXN 6.25 kHz-spaced channels, which
essentially makes them location-independent.
The Icom IDAS™ system
Icom’s implementation of NXDN CAI
Permits IP packet switching without going
to baseband audio
Allows PC nodes
Any PC can serve system-IP trunking
Requires ~13 kbps per connection
Icom
IDAS
intrabuilding
radio
service
Image courtesy Icom
Icom
IDAS
crossband IP
radio
service
Image courtesy Icom
Icom
IDAS
system
enables
voting
via IP
Image courtesy Icom
What’s so great about NXDN?
Networked LMR over IP pricing
IP access cost already paid by user
Pricing locally determined
Only local maintenance costs required
What’s so great about NXDN?
Networked LMR over IP Territory
Ubiquitous, can use dialup for IP and
satellite for RF
Can network any radio channel
Matches local propagation characteristic to
available spectrum
Instantly reconfigurable
What’s so great about NXDN?
Networked LMR over IP Hardware
Any smartphone with a push-to-talk
application
Any radio with a connected base station
Any PC
Packets well understood
Who can I talk to?
The LMR over IP Advantage
Any participating user
Any smartphone user with a push-to-talk
application
Any location with any radio channel
Any PC
Why do I want it?
The Push-to-talk Advantage
Immediate, no dialing, ringing etc.
Conference calling always included, with
balanced audio levels, no setup required
Setup may be done by LMR dealer, user
or any third party
Familiarity in LMR situations
Hardware
Software
Conceptual Convergence
“Smart” repeaters can now interface with
all other smart devices:
Smartphones (iPhone, Android,
Windows Mobile)
PC’s, netbooks
Smart devices may now act as radio nodes
providing IP access
Bluetooth, WiFi, etc.
Hardware
Software
Conceptual Convergence
Radios and repeaters will be automatically
upgraded via IP and/or radio: new standard
at http://RadioSoft.com/ETSI-RRC.pdf
Channelization and modulation controlled
By input radio signal
By software updates
By talkgroup server
Other Benefits of LMR-IP
Convenient
Immediate, no dialing, ringing etc.
Conference calling always included, with
balanced audio levels, no setup required
Talkgroups can be assigned by LMR
dealer, user or any third party
Familiarity in LMR situations
How to Build LMR-IP
Strategy
Create umbrella organization
Develop “smart” cards for repeaters
Enlist spectrum stakeholders
Market, market, market
Thanks
Thanks for taking a look at the possibilities
and promise of NXDN LMR over IP;
Thanks for not falling asleep during the last
eighteen minutes; and
Thanks to all the folks at the Radio Club of
America, who did all the behind-the-scenes
work to this presentation possible.
Questions? Interested, or know someone who would be?
Call 706.754.2725 or write [email protected] to
discuss any time, or check out Push-to-talk.org