October Update 2019

2019 -2020 Platinum Partner - AC-WB Technologies

 
RFUANZ is pleased to announce that our 2019-2020 Platinum Partner is AC-WB Technologies!
AC-WB Technologies Limited is a Warren and Brown Company and was originally established in 1991 as AC&E Sales Ltd - a specialist supplier of precision RF connectors, high-performance coaxial cables, fibre optic cabling and connectors, twisted pair copper cables, data connectors, racks and outside plant equipment. More recently, due to the continuing success, AC-WB Technologies has expanded it's offering into services and solutions and has established a specialised manufacturing and assembly division. Read more about AC-WB here.
 
We are very excited to be working with AC-WB and look forward to hosting you at next year's Gala Dinner. Thank you AC-WB for your support
 

Want to join the PARTNERSHIP CLUB?! Why not - get involved!

RFUANZ has a number of partnership positions available for the upcoming year. Please make contact with Candice or Debby to secure your place - they are going quickly. Thank you to all the companies that have already secured their positions for 2020 - we truly appreciate the ongoing support. 
 
Silver Partners - 3 Remaining
$2500+gst
Silver Partners are a fantastic away to gain exposure at the Gala Dinner while being mindful of your marketing budget.
Your company logo and two images will be projected to our 200+ guests throughout the evening. You will also gain year-round exposure through the RFUANZ website, social media & digital email campaigns.
 
 
Bronze Partners - 6 Remaining
$550+gst
Bronze Partners are a fantastic away to gain exposure at the Gala Dinner at a reduces investment cost.
Your company logo will be projected to our 200+ guests throughout the evening as well as your logo displayed a gala dinner table. We also display your logo on the RFUANZ website for 12 months. 

 
Electrotechnology Level 3 Installer Training

Are you looking at upskilling your employees to better suit the needs of your company and the industry?
RFUANZ in conjunction with Shift E-tec can offer you a course that can be undertaken online and at your employees’ own pace. However, the quicker they complete the course the sooner they will achieve their qualifications and be more beneficial to your company. The training programme is designed to benefit school leavers up to experienced but not yet qualified technicians.
We have been advised by Shift E-tec that sponsorship opportunities may be available to apprentices if required. This is in addition to the two Scholarship opportunities provided by RFUANZ  on completion of the course
 
For more information on the course, contact Debby Morgan on admin@rfuanz.org.nz or visit the Shift E-tec web site
 

COVERAGE THEORY:

The Important Differences between Digital Voice and Data Specification
 
DMR and P25 digital radio standards are specifically designed to provide voice coverage very similar to their analogue narrowband FM predecessors. This means that migration from analogue narrowband FM voice systems to more spectrally efficient, data capable DMR or P25 networks does not require additional repeater sites.

However, when specifying or designing digital radio networks for data transmission, there are important coverage differences that you need to understand, to be sure you specify for the overall network performance you need.
 
First, let’s define some typical performance metrics:
Voice network performance is usually defined as a Delivered Audio Quality (DAQ);
data performance is normally defined by Message Error Rate (MER).
For voice, a DAQ of 3.4 (speech understandable without repetition, although some noise or distortion present) is acceptable for most Public Safety applications. This equates to a Bit Error Rate (BER) of around 2% – two out of every 100 bits received are decoded incorrectly. The decoded audio is noticeably distorted but is still perfectly understandable to the human ear.
Things are not so simple with data, unfortunately. For example, if a data message is 1000 bits long, then that same 2% BER will correspond to an average of 20 errors. Even with Forward Error Correction (FEC) techniques, a BER of 2% means few (if any) 1000-bit messages will be received correctly. That 2% BER equates to nearly 100% MER!
 
Let’s look at it the other way around. If, for example, we decide that MER of 1% is acceptable, that means only one 1000-bit message in 100 is received incorrectly – conceivably, only one bit in 100,000 has been received incorrectly. So, our 1% MER equates to a BER of just 0.001%.
In terms of the acceptable received signal level, for a DMR voice network to achieve DAQ3.4, the signal must be at least 15.6dB above the noise and interference present, the carrier-to-noise ratio (CNR) must be greater than 15.6dB. For a DMR data network, the minimum CNR will depend on message length; the longer the message, the greater the CNR required to achieve the desired 1% MER.
 
 
This reinforces an important difference: for DMR voice there is a single CNR threshold, whereas DMR data networks must be designed with the longest message length in mind, because the threshold varies with message length. Typically, the acceptable CNR for DMR data performance needs to be 10–15dB higher than it does for DMR voice.
 
Now let’s bring it back to what really matters—coverage. If we look at line-of-sight coverage according to free space path loss (FSPL), and the data network requires CNR 10dB higher than voice to achieve 1% MER, the resulting coverage radius will only be 30% of that for DAQ3.4 DMR voice (or 10% of the covered area). For longer message lengths – where the CNR requirement is 15dB higher than for DMR voice – the coverage radius will only be 17% of that for voice. That’s just 3% of the covered area.

 

WHAT DOES THIS MEAN IN REAL TERMS?

Luckily, the news isn’t quite as bad as these theoretical figures suggest. In practice, over real terrain with no line of sight, the covered area differences would be less, but would still be significant and will vary depending on the type of terrain. Similarly, there are technical solutions that can narrow the coverage gap further, e.g. involving technology selection system design, and at product level. That’s why it’s critical that you consult coverage experts when you are investing in a new digital radio network.
 
Mike Head
Tait Communications Ltd
Committee Member – RFUANZ
 
This article was originally published in the Tait Connection Magazine and was written by Principal Engineer Ian Graham