The Rebirth of LMR

A Presentation for the Radio Club of America

100th Anniversary Symposium, November 21, 2009

Presented by Peter Moncure, VP RadioSoft8900 Dick’s Hill ParkwayToccoa, GA 30577PMoncure@RadioSoft.com

In this presentation, I will:

Describe NXDNDiscuss its latest advancementsExplore the possibilities for local radio shops of true IP-based LMRSuggest 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-StarBitrate (DV mode) improved from 2.4 kbps to 4.8 kbpsUnderlying 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.

Note: in this example, the frequency centers are 3.125 kHz offset from FCC designated channel center frequency

Image courtesy Icom

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 FMData 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 voice8K30F1D 12.5 kHz single channel digital data8K30F1W 12.5 kHz single channel digital voice and data4K00F1E 6.25 kHz single channel digital voice4K00F1D 6.25 kHz single channel digital data4K00F1W 6.25 kHz single channel digital voice and data4K00F2D 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 CAIPermits IP packet switching without going to baseband audioAllows PC nodesAny PC can serve system-IP trunkingRequires ~13 kbps per connection

IcomIDASintra-

buildingradio

service

Image courtesy Icom

IcomIDAScross-

band IP radio

service

Image courtesy Icom

IcomIDAS

systemenables votingvia IP

Image courtesy Icom

What’s so great about NXDN?

IP access cost already paid by userPricing locally determinedOnly local maintenance costs required

Networked LMR over IP pricing

What’s so great about NXDN?

Networked LMR over IP Territory

Ubiquitous, can use dialup for IP and satellite for RFCan network any radio channelMatches local propagation characteristic to available spectrumInstantly reconfigurable

What’s so great about NXDN?

Networked LMR over IP Hardware

Any smartphone with a push-to-talk applicationAny radio with a connected base stationAny PCPackets well understood

Who can I talk to?

Any participating userAny smartphone user with a push-to-talk applicationAny location with any radio channelAny PC

The LMR over IP Advantage

Why do I want it?

Immediate, no dialing, ringing etc.Conference calling always included, with balanced audio levels, no setup requiredSetup may be done by LMR dealer, user or any third partyFamiliarity in LMR situations

The Push-to-talk Advantage

Hardware Software

“Smart” repeaters can now interface with all other smart devices:

Smartphones (iPhone, Android, Windows Mobile)

PC’s, netbooksSmart devices may now act as radio nodes providing IP access

Bluetooth, WiFi, etc.

Conceptual Convergence

Hardware Software

Radios and repeaters will be automatically upgraded via IP and/or radio: new standard at http://RadioSoft.com/ETSI-RRC.pdfChannelization and modulation controlled

By input radio signalBy software updatesBy talkgroup server

Conceptual Convergence

Other Benefits of LMR-IP

Immediate, no dialing, ringing etc.Conference calling always included, with balanced audio levels, no setup requiredTalkgroups can be assigned by LMR dealer, user or any third partyFamiliarity in LMR situations

Convenient

How to Build LMR-IP

Create umbrella organizationDevelop “smart” cards for repeatersEnlist spectrum stakeholdersMarket, market, market

Strategy

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 PMoncure@RadioSoft.com to discuss any time, or check out Push-to-talk.org