Evaluating the Nova Roams
We tackled the job, on Sunday, while none of the Trout Lake staff
was around of testing out a new pair of 902-928Mhz radios called
Nova Roam Radios from Nova Engineering. We didn't need the Trout
Lake staff for all we were trying to do is to configure these
new and interesting radios and give them a head-to-head comparative
test of their range and vegetation-handling capabilities with
the known abilities of the 902-928Mhz 1 Watt Freewaves over the
same terrain and lakes.
One
of the tasks I gave young Margot Bergstrom, the undergraduate
research assistant at Trout Lake the previous summer was to 'map'
the limits of the Freewave radios determining a good connection
outward from the central 120 foot mast antenna and base radio
at Trout Lake. She did a good job - by driving around the periphery
out to about 3 miles embracing 7 of the primary study lakes, and
recording on USGS maps and tabularly where the radios remained
connected and where they failed. So we had a benchmark against
which we could test the Nova Roams, which in frequency and near
power, were comparable.
We used the same measuring points to test the NovaRoam 900s, whose
radio characteristics were reportedly similar to the Freewaves.
But
the NovaRoam radios possess other important characteristics that
give it great potential. First they are true 'IP' routing radios
unlike the Freewaves. A limitation of the Freewave radios is that
they not only cannot contain IP numbers in the radio, in anything
other than a point-to-point mode, they do a poor job of handing
IP traffic.
The
Nova Roam radios not only handle IP Traffic, they actually are
called 'routers' because they can route traffic, and contain three
internal 'networks' - each can be on a separate network of their
own.
Here
is a summary of comparative features.
| |
Freewave
|
Nova
Roam
|
| Frequencies |
902-928Mhz
|
902-928Mhz
|
| Power |
1
watt |
.8
watt |
| MaxData
Rate |
115kbps |
1mb
|
| I/O
|
Serial
|
Serial,
Ethernet |
| Link
Indication |
Link
Light |
Ping,
through computer |
| Modes
|
Point
to Point |
Point
to Point |
| |
Point
to Multipoint |
Point
to Multipoint |
| |
Repeater
|
Repeater,
Mesh |
|
Multi-hop
Protocols
|
Frequency
Hopping |
Direct
Sequence |
| |
|
TCP/IP
|
| Routing |
Proprietary
Method |
IP
Routing |
| Access |
Attached
Serial Cable |
Attached
Serial Cable
|
| |
|
Ethernet
Telnet, cable or radio |
| Configuration
|
Terminal
Mode Menu |
Terminal
Mode Menu |
| |
|
Ethernet
Menu |
| |
|
Telnettable
Menu |
| |
|
CD-Ethernet
Utility |
| Other
Special Modes |
|
TORA
- mesh-repeater
|
Now
it took us more time than we wanted to get the two radios configured
right - for, being true 'routers' we got lost in the 'router programming
world' the minute we put unique IP network sets into them - and
take into account that the 'radio' IP configuration is separate
from the 'Ethernet' configuration of the same radio!
Configuring
the Nova Roam Radio
Once
configured we mounted the base radio on the same 120 foot antenna
tower, with 150 feet of LMR600 (the best, lowest loss cable, available)
running to its 4db omni antenna on top.
Top of 120' Antenna Tower at Trout Lake
Then
we piled into my rental sedan, myself driving while Tom Williams
both helped navigate to various lakes from the road maps and held
the 10db yagi antenna outside, while Mike Willett in the back
seat, using cigarette lighter power to run the Nova Roam radio
and his own laptop ethernet connected to it, did repeated Pings
to determine whether we had a connection from each place we stopped.
This
latter was necessary, because the Nova Roam - like most radios
unfortunately - does not have any 'link lights' on its panel.
So the only way you know you are connected is by connecting a
computer to the radio, accessing its administrative menus, and
then sending Pings (or other data which will echo back) to the
other radio, by IP number! That is a MAJOR inconvenience, in comparison
with the Freewave, and its' green 'link light' which permits one
to just carry the powered radio and antenna, and not a computer,
to get proof of connection.
In
fact the absence of such a link light on many field radios is
what motivated me to have a Range Tester device built for use
in siting radio pairs. The next report will report on this useful
device.
Disappointing
Results
We
knew that the Nova Roam radio, even at 902-928Mhz, and with .8
of a watt of power at the radio, with a 10db gain yagi antenna,
would not match the performance of a Freewave by the time we got
to the parking lot of Sparkling Lake. There simply was no link
from the same place we can get a Freewave link.
One
difference was, however, that we had 25 feet of LMR400 cable,
with the FCC required 'proprietary' connector on the radio we
carried around the lakes, and the base Nova Roam was connected
by a 50 foot additional cable, to the 150 foot LMR600 run up the
mast.
Because
the FCC insists on a proprietary connector between the Nova Roam
and any standard antenna cable, I had been compelled to buy the
two pieces of cable, with the Nova Roam connector at one end and
a standard 'N' male connector at the other. But the added loss
in those lines was simply too great for the radios, when going
through the additional 150 feet to the tower, and the trees.
We
decided this was not a true test. So we had to return to the Trout
Lake Station, where Mike Willett cut the costly pre-made cables
($200 worth), and made (soldered) two very short - 2' - cables,
and we tried again. This 'proprietary' connector business is the
most frustrating, time consuming, and costly part of doing site
surveys. And the purported reason the FCC requires this of all
radio manufacturers is to deter amateurs from buying standard
'N' connector cables and antennas which may exceed the 4 watts
EIRP rules, and using them. But it's a real pain.
There
had been rain in the area, which could have attenuated the signal
greatly while the leaves were still wet, but that factor diminished
as the day wore on into early evening when we stopped.
The
shortened cables made a big difference, but we still could not
get a link to Sparkling Lake with one Nova Roam on the tower antenna,
and the other at the edge of the lake, where we had a Freewave
deployed on the raft on the lake the last winter. We knew then
that the Nova Roam radios simply are not as receiver-sensitive
as the Freewaves. Big disappointment.
But
we continued around Trout Lake, and stopped at each point where
the Freewaves had been able to operate - or not reach, as the
case may be - but which represented points at which Data Loggers
were, or were desired by the Researchers, to be placed.
We
had success across Trout Lake from sites on the west side of the
lake, including Trout Bog, but no success on the eastern side
of the lake, or Crystal Lake.
No
Link Across Crystal Lake
We
also failed to get a link from the northernmost tip of Trout Lake,
4.7 miles from the tower - through a narrows with trees - where
previously we had gotten a Freewave link - though it was marginal.
Testing
4.7 Miles Across Trout Lake
Thus,
after several hours of link tests, we concluded that the Nova
Roam radios operated at only about 80% of the link-strength of
Freewaves in the same area. Thus, while they could be very useful
closer in - more like a 2 mile radius and for tasks requiring
IP connectivity, while the Freewaves approached 3 miles through
the same forests - they were not a complete substitute for Freewaves
through vegetated research areas.
We
did call Nova Roam's engineers on Monday, to see whether we were
missing anything in our configuration of the radios. But having
them set at the 159kbs power/channel setting, we indeed had been
operating at the peak radio capabilities of the Nova Roams.
Nova Engineering Link www.nova-eng.com
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