Hi foks,
Apologies for the cross-list posting, but I hope that someone on one of
these lists might be able to help me and that hopefully many folks on both
lists are interested in this question.
We are installing a networked clinic system in rural Zambia using the cell
network and GPRS modems to talk to each other. As we got out to the sites,
however, we realized that coverage has not been as good as advertised, and
while we can find spots to use our phones around the area, in many cases the
places where we're keeping our computers and modems to not have enough
coverage to reliably connect.
I'm wondering if anyone has had to solve this type of problem, and if so
what our options are or recommendations of things that work to increase the
network strength might be. Currently we are using Huawei e1550 usb stick
modems and are considering:
- GSM modem antennas. These seem like the most obvious solution: antennas
that plug into a special slot in the modem. Unfortunately our current
modems don't have ports for external antennas so this would mean buying a
bunch more hardware. Anyone used these before? I assume they work pretty
well? Any particular model or brand recommendations?
- Clip on antennas. These would work with our current modems - basically
you wrap some wire around the modem and it leads to an antenna that you can
hang by the window. Sounds super-sketchy to me, but maybe they work?
- Standalone cell signal boosters. It seems like these are designed more
for homes where you want to spread the signal around a larger area, but it
does have the benefit of also boosting network for the rest of the folks at
the clinic, and maybe will get the job done. Again - do they work? Any
particular recommendations?
- Something else?
We're trying to learn as much as we can over the internet, but if anyone has
any first hand experience trying to solve this problem it would be much
appreciated.
thanks in advance,
Cory
···
--
Cory L. Zue
Dimagi, Inc
http://www.dimagi.com/
External antennas seem like the cheapest and most effective solution
to me. You may want to do a bit of research on the e1550's, a lot of
the modems don't have external connectors, but do have them available
inside with a tad of solder. (e220 being one) Looks like the E156G is
the same modem with an external connector though, so that might be an
easier route. Once you have that a YAGI should work pretty dang well.
I can't imagine the external wire wrap method makes much difference at
all. Let us know how it turns out, I'm curious to hear.
-Nic
···
On Tue, Aug 24, 2010 at 9:37 AM, Cory Zue wrote:
> Hi foks,
> Apologies for the cross-list posting, but I hope that someone on one of
> these lists might be able to help me and that hopefully many folks on both
> lists are interested in this question.
> We are installing a networked clinic system in rural Zambia using the cell
> network and GPRS modems to talk to each other. As we got out to the sites,
> however, we realized that coverage has not been as good as advertised, and
> while we can find spots to use our phones around the area, in many cases the
> places where we're keeping our computers and modems to not have enough
> coverage to reliably connect.
> I'm wondering if anyone has had to solve this type of problem, and if so
> what our options are or recommendations of things that work to increase the
> network strength might be. Currently we are using Huawei e1550 usb stick
> modems and are considering:
> - GSM modem antennas. These seem like the most obvious solution: antennas
> that plug into a special slot in the modem. Unfortunately our current
> modems don't have ports for external antennas so this would mean buying a
> bunch more hardware. Anyone used these before? I assume they work pretty
> well? Any particular model or brand recommendations?
> - Clip on antennas. These would work with our current modems - basically
> you wrap some wire around the modem and it leads to an antenna that you can
> hang by the window. Sounds super-sketchy to me, but maybe they work?
> - Standalone cell signal boosters. It seems like these are designed more
> for homes where you want to spread the signal around a larger area, but it
> does have the benefit of also boosting network for the rest of the folks at
> the clinic, and maybe will get the job done. Again - do they work? Any
> particular recommendations?
> - Something else?
> We're trying to learn as much as we can over the internet, but if anyone has
> any first hand experience trying to solve this problem it would be much
> appreciated.
> thanks in advance,
> Cory
> --
> Cory L. Zue
> Dimagi, Inc
> http://www.dimagi.com/
We deployed external directional antennas for GSM/3G USB modems in the
Philippines after finding that the signal inside of our clinics were
unreliable and highly location dependent. They made a significant
difference, were locally available, very simple, and cost around $40 if
I remember correctly. Keep in mind that you should minimize antenna
cable lengths whenever possible to avoid signal loss on the cable. Local
laws do apply, but forgiveness tends to be easier than permission.
We bought our equipment from these Filipino suppliers:
http://www.roughclaw.com/Products--and--Services.php. The product code
is RCA-PDA002-08. (which I don't see on the site right now)
We were using a SmartBro (local mobile network operator) branded (and
locked) Huawei HSDPA Modem Model MF622. We connected the modem to a wifi
router which provided coverage for the entire clinic, and allowed us to
place the router close to the window that the antenna cable ran through
to its mounting point just outside. (I can probably find a picture if it
would help)
I would be happy to connect you to my colleague in the Philippines who
procured and deployed this.
Mike
···
On 08/24/2010 03:37 AM, Cory Zue wrote:
> Hi foks,
>
> Apologies for the cross-list posting, but I hope that someone on one
> of these lists might be able to help me and that hopefully many folks
> on both lists are interested in this question.
>
> We are installing a networked clinic system in rural Zambia using the
> cell network and GPRS modems to talk to each other. As we got out to
> the sites, however, we realized that coverage has not been as good as
> advertised, and while we can find spots to use our phones around the
> area, in many cases the places where we're keeping our computers and
> modems to not have enough coverage to reliably connect.
>
> I'm wondering if anyone has had to solve this type of problem, and if
> so what our options are or recommendations of things that work to
> increase the network strength might be. Currently we are using Huawei
> e1550 usb stick modems and are considering:
> - GSM modem antennas. These seem like the most obvious solution:
> antennas that plug into a special slot in the modem. Unfortunately
> our current modems don't have ports for external antennas so this
> would mean buying a bunch more hardware. Anyone used these before? I
> assume they work pretty well? Any particular model or brand
> recommendations?
> - Clip on antennas. These would work with our current modems -
> basically you wrap some wire around the modem and it leads to an
> antenna that you can hang by the window. Sounds super-sketchy to me,
> but maybe they work?
> - Standalone cell signal boosters. It seems like these are designed
> more for homes where you want to spread the signal around a larger
> area, but it does have the benefit of also boosting network for the
> rest of the folks at the clinic, and maybe will get the job done.
> Again - do they work? Any particular recommendations?
> - Something else?
>
> We're trying to learn as much as we can over the internet, but if
> anyone has any first hand experience trying to solve this problem it
> would be much appreciated.
>
> thanks in advance,
> Cory
>
> --
> Cory L. Zue
> Dimagi, Inc
> http://www.dimagi.com/
> --
> You received this message because you are subscribed to the Google
> Groups "rapidsms" group.
> To post to this group, send email to rapidsms@googlegroups.com.
> To unsubscribe from this group, send email to
> rapidsms+unsubscribe@googlegroups.com.
> For more options, visit this group at
> http://groups.google.com/group/rapidsms?hl=en.