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PPP-GPRS protocol for MG100



1. Introduction

PPP-GPRS protocol is identical with the PPP protocol for MORSE, in
addition uses the menu SXe.

MG100 is a variation on the MR400 radiomodem, equipped with GPRS in
place of the radio part. It allows for connecting points of the data
network via the GPRS network or inserting a GPRS section into the MORSE
network transmission path.

2. Data Format

The data format is similar to the PPP protocol. A more detailed
description is contained in article Format of the UDP datagram IPGW for
MORSE. The PPP protocol is used in the M-IP-M mode.

3. Implementation in the MORSE System

Regarding HW the modem board is connected to the GPRS module through
the SCC1 channel, which is why it is unavailable to the user. SCC2, SCC3,
and ETH0 channels and the ADIO analog and digital I/O module are
available. The SCC0 channel can be used subject to SCC0 being out of
operation for the time the service cable is connected.

Modem communication with the GPRS module is indicated by three LEDs
located by the antenna connector:


– GPRS status


– transmitting packets from the modem to the GPRS


– receiving packets from the GPRS module to the modem

SW control is carried out using the PPP protocol by selecting
parameter “(g)prs mode:ON“. Functions controlling the radio
part, which are contained in the SETR Main menu, are not functional. For
example, instead of monitoring the radio channel we use
iMSIe1r” for monitoring communication with the

The GPRS module can have an assigned static IP address. It is then
always available to all network subscribers and is listed in their Art

  • as “default gw” in case it is the only owner of a fixed IP

  • or in a pair with a MORSE address

       dest:    gw:
       69000001 C0A80005
       69000002 C0A80016

    in the case of more known subscribers.

There must be at least one module with a static address in the

If the GPRS module has an assigned dynamic IP address which changes
on each new login it must report at regular “(p)roxy timeout
intervals to the address of the module with the fixed address, which then
maintains a list of other subscribers in the Art

The module can be put into idle mode by entering the specific
password “(s)ms passwd“. It can be reactivated by sending an
SMS with the password to its telephone number.

4. Configuration

When configuring the MG100 connect the network output of the node to

Nodes:                         retab
Nid|address |M | u   s | L   N |l w n g|sTO Err  Cent vTO hTO
(0) 00461B02     -  S00| -  R00|0 0 0 0| 15 SERV  OFF 304  30
(1) 6981AA01    S02 S00| -  S01|0 0 0 0| 15 SERV  OFF 304  30
(2) 00000000    S01 S00| -  R02|0 0 0 0| 15 SERV  OFF 304  30
(3) 00000000    S02 S00| -  R03|0 0 0 0| 15 SERV  OFF 304  30
(4) 00000000    S03 S00| -  R04|0 0 0 0| 15 SERV  OFF 304  30

  SIe 1rN1

Channel to Node Interface:
    retranslation     |   user+service             lim
 id N  A t          m | N  A t Base     m  sec brc S   e
(0) 0   NO AR         | 1   NO AR          usr OFF NONE
(1) 1   NO AR         | 2 MASK 00000000/08 usr OFF NONE
(2) 0   NO AR         | 1 MASK 00000000/08 usr OFF NONE
(3) 0   NO AR         | 0 MASK 00000000/08 usr OFF NONE

Select the communication speed on SCC1 according to the GPRS module,
idle to 200 and the PPP protocol:

   SPe 1b1152

Since 07/2010 are GPRS routers MG100M2 and MG100M3 configured to
higher speed on the SCC1 port:

   SPe 1b2304

    n     m     g    b   p8   i   s  XRC D G  o
(0)RS232 ASYNC  SW  19200N81  5 1600 --- D 0 MARS-A
(1)RS232 ASYNC  SW 115200N81 200 1600 --- D 0 PPP
(2)RS232 ASYNC  SW  19200N81  5 1600 --- D 0 MARS-A
(3)RS232 ASYNC  SW  19200N81  5 1600 --- D 0 MARS-A

Set PPP protocol parameters (L)oc IP and (R)mt
to zero, mr(u):1500, (h)ayes simulator:OFF a (g)prs

[Important] Important

It is necessary set a non-zero value in (R)mt IP for the router

PPP parameters:
Wanted options:
(L)oc IP:00000000h        
(R)mt IP:00000000h        
Got options:
(h)ayes simulator:OFF
LCP m(a)gic:ON    obsolete LCP ma(G)ic (sv465..sv479):OFF
(g)prs mode:ON  (i)nfo

The items “Got options:” are filled in automaticaly
after connecting to the BTS.

The current overview of accessible BTS, the information about the
module used and PPP protocol state provides the “(i)nfo
menu, e.g.:

Example for MG100M1… router, which is attached to GSM/GPRS
network. Timeout SXe r 1go = 120 sec, row S denotes the
active BTS:

>>GPRS info: RSSI -61 dBm; registered home; GPRS attached.

#MONI: EUROTEL - CZ BSIC:17 RxQual:0 LAC:0725 Id:20A7 ARFCN:48 PWR:-60dbm TA:0
#MONI: Cell  BSIC  LAC  CellId  ARFCN    Power  C1  C2  TA  RxQual  PLMN
#MONI:  S    17  0725   20A7      48   -60dbm  45  45   0     0    EUROTEL - CZ
#MONI: N1    11  0725   95D7     520   -73dbm  17  33 
#MONI: N2    16  0725   20A5      93   -88dbm  17  11 
#MONI: N3    15  0725   0000     112   -95dbm  10   4 
#MONI: N4    11  0725   95D5     524   -96dbm  -6  -12 
#MONI: N5    16  0725   209A      41   -98dbm   7   1 
#MONI: N6    15  0725   20C0      87   -99dbm   6   0 

next info in 87 sec (of 120)
DEBUG: gprs_state 9, grps_attached 1, t0_state 0, last_itime 3s
DEBUG: next dehryz in 1163 sec (of 1200)

Example for MG100M2… router,, which is attached to UMTS
network. Timeout SXe r 1go = 0 sec, only the active BTS is

>>GPRS info: RSSI -65 dBm; registered home; GPRS attached.

#MONI: EUROTEL - CZ PSC:53 RSCP:-73 LAC:0EE3 Id:ED99CFF EcIo:-9.5 
   UARFCN:10564 PWR:-64dbm DRX:32 SCR:848

DEBUG: gprs_state 9, grps_attached 1, t0_state 0, last_itime 7s
DEBUG: next dehryz in 294 sec (of 300)

In menu IPG(W) select the M-IP-M mode and
long (t)imeout:8000 :

  (A)rt:1; write (E)nable:ON
  (r)epeats:0002  (t)imeout:8000  (p)roxy timeout:300s
  (f)rag size:1500bytes  (g)lue (append) up to:0packets

(p)roxy timeout:300s is used for the GPRS module with a
dynamic IP address and (p)roxy timeout:0s is sufficient for
static addresses

There are three basic ways of filling in the Art table which menu
M-IP-M refers to:

  1. the GPRS module is the only one assigned with a static IP

    • table Art is empty, and is filled in automatically after
      logging in other modules

  2. the GPRS module has an assigned dynamic IP address:

    • the IP address of the module, which has a static IP address,
      is written to “default gw” in the Art table; see
      example. This module with the static IP address then becomes the

  3. more modules have static IP addresses:

    • fill “dest” and “gw” in the Art
      table so that we get a translation table where the column “dest”
      contains MORSE address and “gw” the respective IP
      addresses of other known CUs having the static addresses.

ART No 1: 
items: 0
default gw: C0A81234 (  )
dest:    gw:

Special parameters for the GPRS mode are found in menu: SXe

[Important] Important

Do not use the Init and Sync command in this menu. After choosing
SXe” read the current state using “r
=(r)ead, continue “1g“. The new parameters
save by “w“. Next, do (I)nit the menu SPe or
total reboot.

(i)nit string (&K0\Q0&D0&C1):               
(A)PN string:
(s)ms passwd:      
inf(o) timeout:1800
(d)ehryz timeout:1200
d(e)hryz mode:MODULE RESET+WARM RESTART (MG100i only)

(i)nit string (&K0\Q0&D0&C1):               
(A)PN string:                              
(w)ireless service select:AUTO
ope(r)ator select:AUTO
oper(a)tor code:0
(s)ms passwd:      
inf(o) timeout:1800
(d)ehryz timeout:1200
d(e)hryz mode:WARM RESTART
(i)nit string

– AT commands which are executed on initialising the
connection can be prepared here. We recommend for routers MG100i
since version fw

  • MG100x0: “ 

  • MG100x1,2,3:

  • MG100x4: “&C1


– f the SIM card uses a PIN, enter it here. On entering an
incorrect PIN there is a risk of blocking the SIM card!

(A)PN string:

– name used by the APN network, e.g.: profi.internet,


–login number to the network, e.g.:

(w)ireless service
  • (0) AUTO – volí přednostně UMTS, pak

  • (1) GPRS/EDGE (2.5G)

  • (2) UMTS (3G)

    – volba módu, pro MG100x2, MG100x3

  • (0) AUTO – automaticaly

  • (1) MANUAL/AUTO – preferably to
    oper(a)tor code

  • (2) MANUAL – according to oper(a)tor

– volba operátora, pro MG100x1,2,3,4

oper(a)tor code:0

– code for the ope(r)ator select, e.g. 23002

(s)ms passwd:

– content of SMS message (min. 6 characters) to activate CU
from idle state. After entering parameter “(s)ms
” and initialising the protocol the CU is put into
idle state.

inf(o) timeout:

– for testing. With period “inf(o) timeout:
short jumps to “command mode” are made with the new
record about the connected BTS station. However, there is
approximately a 5 second communication delay, which is overcome by
means of timeouts on PPP. Records can be read using the
SPe1ti” command and takes effect on RSS LEDs also. For
tuning purposes use inf(o) timeout:30 sec, for standard
operating around 1000 sec. RSS state can be refreshed using the init
of PPP protocol.

MG100x4: inf(o) timeout:0 – the used module does
not support this function

(d)ehryz timeout:

– the CU monitors the incoming IP packets. If no packet
arrives over the “(d)ehryz timeout” period then the
restart according to next parameter is executed

d(e)hryz mode:
  • (0) WARM RESTARTInit is
    executed and an entry is made to the Event

  • (1) POWER CYCLE+WARM RESTART – both voltage
    restart of GPRS module and modem restart (protocol
    Init is executed and an entry is made to the
    Event log)

    – hardware RESET of module is executed and warm
    restart of modem (Init is executed and an entry is
    made to the Event log)

    – this is the recomended choice for new routers

5. History

  • 11/2005 – release 740 – new description

  • 08/2007 – BTS info example

  • 05/2009 – release – MG100i routers – menus SPe
    1tL, SXe r 1ge

  • 03/2010 – release – router MG100M4 – (i)nit string,
    inf(o) timeout

  • 07/2010 – speed 230.4 kbps on SCC1 for MG100M2 and

  • 12/2010 – (w)ireless service select, ope(r)ator select –