SIM700D: What should the min signal quality be for GPRS?

EDAboard.com Forum Index -> Professional Hardware and Electronics Design -> SIM700D: What should the min signal quality be for GPRS?

Author

Message

BasePointer

Joined: 03 Jul 2002
Posts: 124
Helped: 3
Location: TURKEY

21 May 2009 8:56 SIM700D: What should the min signal quality be for GPRS?

Hi,

What should the min signal quality be for proper GPRS connection?

My SIM700D returns (22,0) for AT+CSQ.

RSSI = 22
BER = 0

Are these values ok?

Code:

Parameters for AT+CSQ
<rssi>: 0 -113 dBm or less
1 -111 dBm
2...30 -109... -53 dBm
31 -51 dBm or greater
99 not known or not detectable
<ber> (in percent):
0...7 as RXQUAL values in the table in GSM 05.08 [20] subclause 8.2.4
99 not known or not detectable

Also I wonder, can I measure impedance of antenna path at real PCB or Can I detect if there is a mismatch?

10x,
BP.

sabeti_1990

Joined: 16 Nov 2007
Posts: 178
Helped: 11

02 Jun 2009 9:39 SIM700D: What should the min signal quality be for GPRS?

hi
yes the values are OK
U don't need pcb for antenna use a 50 ohm coaxiall cable to transfer signal of antenna
it's better that don't use PCB for this

Google
AdSense
Google Adsense

02 Jun 2009 9:39 Ads

BasePointer

Joined: 03 Jul 2002
Posts: 124
Helped: 3
Location: TURKEY

02 Jun 2009 17:33 Re: SIM700D: What should the min signal quality be for GPRS?

sabeti_1990 wrote:

hi
yes the values are OK
U don't need pcb for antenna use a 50 ohm coaxiall cable to transfer signal of antenna
it's better that don't use PCB for this

Thanks but SIM700D is PCB type and doesn't include any socket for antenna. It has just antenna pad. So we need a route between sim700d antenna pad and antenna socket.