NetMonitor in Nokia phones (2/7)

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Main page

- -NetMonitor in Nokia phones (2/7) - -

[Part 1][Part 2][Part 3][Part 4][Part 5][Part 6][Part 7] - -

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11. Glossary
-

- -

Here you can find explanation to some terms, which can be found in this FAQ: - -

ACCH (Analog Control Channel) -(TDMA 800/TDMA 1900) - -

AMPS (Advanced Mobile Phone Service) -
Analogue cellular system working in 800 Mhz used, for example, in North America. - -

ASIC (Application Specific Integrated Circuit) -
Electronic chips designed for some concrete purposes - (for example, in phone it controlls communication between MCU and DSP) -They're designed and produced by the companies which use them. - -

AVCH (Analog Voice Channel) -(TDMA 800/TDMA 1900) - -

BCC (Base-station Color Code) -(GSM/DCS/PCS) -
3-bit number (from 0-7 range) used to distinguish neighbor cells of the same operator, -transmitting using BCCH in the same -FDMA channel. Such distinguish is not needed when the cells belong to different operators -(they use different channels and their BCCH are in different FDMA channels). -It is given in BSIC of each BTS (you can check it for example in -test 2). - -

BSC (Base Station Controller) -(GSM/DCS/PCS) -
It controls and supervises one or more BTSes. - -

BSIC (Base Station Identity Code -or Base transceiver Station Identity Code) -(GSM/DCS/PCS) -
Unique ID number of each BTS. If we code this value binary, first three digits (in decimal format) -are BCC and next three are NCC. These values range from 0 - 63. -BSIC values can be found among others in test 2. - -

BTS (Base Transceiver Station) -(GSM/DCS/PCS) -
This device allows communication between phones and cellular network -(many parameters, like current communication channel, distance to BTS and signal quality can be found, for example, -in test 1). - -

And here are another classes with maximum power of BTS: - -

- - - - - -
GSM 900 GSM 1800
-320 W (55 dBm)
-160 W (52 dBm)
-80 W (49 dBm)
-40 W (46 dBm) - --
--
--
-- -
-20 W (43 dBm)
-10 W (40 dBm)
-5 W (37 dBm)
-2,5 W (34 dBm) -
- -

In Polish version of this FAQ I give many links to WWW pages with BTS lists, their descriptions, pictures (in Poland). - -

From English pages I recommend www.geckobeach.com/cellular/cellpixs/cellid.htm -site - it's about networks and BTSes in North America. - -

Another links connected with it: - -

http://go.to/nokia.info - photos of BTSes
www.club.cz/nokia.monitor/ -- BTSes bases for Czech networks

- - -

C1 (path loss-criterium) -(GSM/DCS/PCS) -
This is a parameter (ranging from -99 to 99 dBm) calculated by the phone to decide which cells to use -(it uses the cell only if its C1 is positive). This value is based on: - -

RX -
Strength of signal received in BCCH channel. If it is equal or less than -RxLevAm, the phone searches for next -BCCH channel. It is shown in -test 1 (for current channel) -and also in test 3, test 4 -and test 5 -(for neighbor channels). The amount of measurements of the quality of transmission with BCCH channels -in neighbor cells is given in test 62
RxLevAm (Rx Level Access minimum) -
Min. level of the received signal (usually from -100 dBm to -110 dBm) needed by the phone to use particular cell.
MSTxPwr -
Max power, which can be transmitted by phone to get access to -RACH channel (i.e. max power allowed by current cell). -Actually, it is lower in towns (where cells are small) and higher outside them. -
MSMaxTxPwr -
Max permissible transmission power of the phone (its classes are described in -TX description).

- -

It is calculated using following formula: -C1 = (RX - RxLevAm - MAX ( ( MSTxPwr -- MSMaxTxPwr ), 0) ) , where MAX(x,y) is obviously a mathematical -function giving the bigger one of the discussed numbers. -The phone shows C1 value in test 1 (for current channel) and in -test 3, test 4 -and test 5 -(for neighbor channels). - -

C2 (cell-reselection criterion) -(GSM/DCS/PCS) -
This parameter (-99 to 99 dBm) is calculated with following formula: -C2 = C1 + Cell reselect -offset - Temporary offset -* H (Penalty time - T). -If this value for some other cell (C2 for -neighbor channels can be found in test 3, -test 4 and -test 5) is higher than this value for current cell -(shown in test 1 and test 3) -for a period of time longer than 5 seconds, the phone switches cells. There are two exceptions to the rule: - -

if the new cell is located on different Location Area (this parameter for current cell can be checked in -test 11), C2 for this cell must be (during more than 5 seconds) -higher than C2+CELL_RESELECT_HYSTERESIS for old cell (where CELL_RESELECT_HYSTERESIS is a -special parameter sent in BCCH channel).
if the phone switched cells during last 15 seconds, C2 for a new cell must be higher at least 5 dBm from -C2 value of the old cell. -

- -

H(x) function for currently not used cells is 0 (if x<0) or 1 (if x>=0). For current cell H(x) is always equal 0. -
By a skillful manipulation of this parameter (through CELL_RESELECT_HYSTERESIS), operators can direct -connections to specific cells (thus lightening load of the network). - -

CDMA (Code Division Multiple Access; also known as IS-95) -
One of the newer digital technologies in 800 or 1900 Mhz. Used in North America, Australia and some southeastern Asian countries -(e.g. Hong Kong and South Korea). It doesn't divide the radio frequency -spectrum into separate user channels by frequency slices or time slots, but -separates users by assigning them digital codes within the same broad spectrum. - -

DCCH (Digital Control Channel) -(TDMA 800/TDMA 1900) - -

DCS (Digital Cellular System) -
Cellular communication system working in 1800 MHz frequency band -(currently more often called GSM 1800) a changed version of GSM (900 MHz) system. -Its new features allowed to increase network capacity (thats why this system is used in urban areas with huge number -of subscribers) at the cost of thick net of the base stations (BTSes) -and to provide roaming within one country. GSM 1800 has different channel numbers -(see test 17), different phone -(see RX description) and BTSes -transmission power and also different max speed of the user, at which he can use his phone -(250 km/h in GSM and 130 km/h in DCS). - -

DSP (Digital Signal Processor) -
Signal processor (digital signals processing chip - controls radio interface and speech coding/decoding). -Its version can be checked in test 88. - -

DTCH (Digital Traffic Channel) -(TDMA 800/TDMA 1900) - -

DTX (Discontinous Transmission Exchange) -
Some phones and networks "care" ;-) about battery life using so called discontinuous transmission (DTX), -which turns off phones transmitter when we dont talk (but for example - listen to the calling party). -During that period the phone generates a so called comfortable :-) noise, because if our interlocutor heard the silence, -he could think that the connection was broken. - -

(GSM/DCS/PCS): -
DTX must be supported by the phone (Nokia does - see -test 78) and BTS - you can check and -(sometimes) change this in test 12 and -test 13. - -

FDMA (Frequency Division Multiple Access) -(GSM/DCS/PCS) -
This name means multiaccess on frequency field: transmission proceeds on different frequencies at the same time -(this is a "full duplex" connection): there is a down-link from BTS to the phone and -up-link - from the phone to BTS (this is called "up" and "down" because BTS -antennas are usually higher than phone ones, so the signal from BTS to the phone -really must go down (and vice versa)). - -

Frequency hopping (channel hopping) -(GSM/DCS/PCS) -
During connection your phone can continuously change used frequency (used channel) in communication with cell. -It's used, when some channel is still troubled - without channel hopping -communication with phone could not be possible, with it it's - only this -part of transmition, which is made on this frequency, is lost (so, if gives less number of -signal loss, but doesn't change sound quality - methods of coding it are always -the same). You can check (during a call) if your phone uses this function in -test 1. test 12 informs -if it is allowed by the cell (these values are updated only during a call). Channel hopping requires -Hopping Sequence Number (frenquencies are changed according to known for phone and network sequence) -- see test 2. - -

GSM (Global System for Mobile Communication) -
Cellular telecommunication system working at 900 MHz. It also has a 1800 MHz (DCS) and -1900 MHz (PCS) version. - -

HLR (Home Location Register) -(GSM/DCS/PCS) -
Network register containing information about subscribers (i.e. about their subscribed services, -tariff, last network they were logged in, etc.). - -

IMEI (International Mobile Equipment Identification code) -(GSM/DCS/PCS) -
Unique 15-digit identification number of every GSM phone on the world. It can be checked using *#06# code -(all phones) or in service menu (Nokia), which can be activated by typing a code *#WAR0ANTY# or -*#WARRANTY# (Nokia 6130). In Nokia 3110 after entering service menu (*#WAR0ANTY#) -you have to additionally enter a code 9268. IMEI contains information about the manufacturer, -place of production and serial number (check www.tele-servizi.com/janus/texts/imei.txt -for such list for Motorola phones, -here is my list for Nokia phones). -Operators can restrict network access for particular phones for example the stolen ones -(identified using IMEI number). Different operators can exchange such lists too. - -

IMSI (International Mobile Subscriber Identify) -(GSM/DCS/PCS) -
Unique (max 15-digit) number given to the phone: - -

first three digits are MCC
next three digits are MNC
the rest is a unique number

- -

IMSI attach -(GSM/DCS/PCS) -
It is a procedure executed after each power on. The phone informs network that it is active (and is ready for communication -- receiving waiting SMS, etc.) and then it receives the IMSI number. -The counter connected with IMSI attach is located in test 64, -test 7 informs whether this is allowed by the current cell. - -

IMSI detach -(GSM/DCS/PCS) -
The phone informs network that it is going to switch off and the communication wont be possible -(its IMSI expires). The counter connected with IMSI detach is located in -test 64. test 7 -informs whether this is allowed by the current cell. - -

Location Update -(GSM/DCS/PCS) -
Every GSM phone periodically informs network about its current location. -This function is called Location Update. It is executed after changing Location Area (phone makes -it "intelligent" - when it's moved out of network coverage and the logs again to the network, makes Location Update -only when current BTS has different LAC than previous one before losing the signal) or -PLMN (after leaving the range of one network and trying to log in to another). -Then information about Location Update is transferred to a new MSC/VLR, -which in turn passes this information to HLR. When the phone works in new -MSC/VLR, HLR doesnt identify the user by -the number received from old MSC/VLR anymore. Location Update -has a couple of varieties: PLU, IMSI attach and IMSI detach -(they're distinquished in test 64). Current Location Area code can be checked in -test 11. - -

MCU (Master Control Unit processor) -
Main processor in phone. - -

MSC (Mobile Switching Center) -(GSM/DCS/PCS) -
Part of the system responsible for communication between subscribers and other users (also from other networks). - -

NCC (National Color Code or Network Color Code) -(GSM/DCS/PCS) -
3-bit number (from 0-7 range) used to differentiate cells of the operators from different countries -(for example near the border, where the phone is in range of several different networks) transmitting using -BCCH in the same FDMA channel. This number is constant -within PLMN. It is given in BSIC of every BTS -(you can check it in test 2). - -

PLMN (Public Land Mobile Network) -(GSM/DCS/PCS) -
Area covered by one operator (one network). After changing this area, the phone executes -Location Update. - -

Coverage maps of different operators worldwide can be found at www.subcam.freeserve.co.uk/mark/orange/ora.html.

- -

PLU (Periodic Location Update) -(GSM/DCS/PCS) -
The phone informs network, on which country area (in the range of which cells) it is located. -This procedure is executed periodically (depending on the network, for example in polish -Era GSM and -Plus GSM networks every 3rd hour, in -Idea every 2th hour) -- this can be checked in test 10. This period is counted from the -last contact with network (the counter doesnt stop even if the phone loses network signal!) from the last call, sending/receiving -SMS, requesting some services (for example enabling call diverting), because the network is then informed about phones -location (but this is not registered in test 64). -The counter connected with PLU is in test 64. - -

TCH (Traffic Channels) -(GSM/DCS/PCS) -
Two way user data (computer data or digitized voice) channels. They can be divided to: - -

-HR (Half Rate Traffic): max data transfer rate is 6.5 kbit/sec (introduced in -GSM phase 2). HR channels offer worse sound quality but also longer phone standby time (even up to 30%), -because the phone using HR uses less power. The main advantage of this kind of channels is that they -enable the network to double its capacity (the number of subscribers able to make a call at the same time see -TS parameter description for more details) or to double the max range of the -BTS. Using these channels must be allowed and supported by the network (this can be -checked in test 7) and the phone. Activation code is -*HRC0#, deactivation code is #HRC0#. Unfortunately, not all Nokia phones accept these codes -(the phone should reset itself after entering them) in older models they're not supported, in never they're deactivated, when -the phone is directed to countries with networks, which doesn't support it. -Interesting fact is that in Nokia 6110 (firmware 5.24) you can decide whether the phone can use this channel or not by modifying -following EEPROM memory cells values: - - - - - - - - - - - - - -
enabling disabling
cell 0070 value for 78 -
cell 011F value for 84 cell 0070 value for 70 -
cell 011F value for 7C
-
-FR (Full Rate Traffic):transmission at 13 kbit/sec, coding using -LPC-RPE (Linear Prediction Coding with Regular Pulse Excitation) algorithm
-EFR (Enhanced Full Rate): -13 kbit/sek, coding algorithm different than in FR (ASELP (AlgebraicCode Excitation Linear Prediction) -created by Nokia and Sherbrooke University; recognized as an industrial standard for -GSM). EFR provides better sound quality at the same data transmission rate (and up to 5% -faster battery drain compared to FR). This mode can be enabled using -*EFR0# code (the phone then tries to use TCH channels in following order: EFR, FR, -(HR)) and disabled with #EFR0# (order: FR, (HR)). These codes may be not recognized -by some models (for example 6110 with some firmware versions) - -if your phone accepts them, it should reset itself right after typing them -(if this doesnt happen, you wont be able to enable/disable EFR using a keyboard code). -This channel is not supported in all older models (for example, 2110). -The type of channel used by your phone can be checked only during connection. -

- -

When you network doesn't support one of these channel and phone recognizes its activation code, you may see -"Not ready" message. - -

You can check this in test 1. -The sequence of TCH channels can be freely set using some of the service programs -(for example WinTesla in Software/Product Profile menu) - it can be only possibility to enable HR channel in phone. - -

TDMA (Time Division Multiple Access) -(GSM/DCS/PCS) -
This means multiaccess in time: several phones can transmit signal (either digitized voice or computer data) in the -same time on the same channel (its number can be checked in test 1) -actually, this period of time is divided into very small parts (see TS description), -invisible for us, so we can assume it happens simultaneously). - -

TMSI (Temporary Mobile Subscriber Identity): -(GSM/DCS/PCS) -
During signalization procedures encrypted on radio channel -(for example, during location update) this number is assigned by -MSC to phone. In the moment, when network wants to contact -with concrete phone and transmission on radio channel is not encrypted, it's send -instead of IMSI and allows phone to indentify, that concrete -call concern on it. It doesn't have global meaning -and it's structure is definited by network administrator. Actual TMSI -you can check in test 10. - -

TS (Time Slot) -
Each radio channel used in communication between phone and -BTS is divided into 8 parts (called TS - time slots). If in all BTSes -(available for your phone) all time slots are in use, you won't be able to make/receive a call and you'll get a 'Network busy' -message (information about reason of connection failure is given among others in -test 39). Unfortunately, each type of connection has the same priority in -networks not supporting GSM Phase 2+ (it isn't available in older GSM Phases) - so if you want to dial emergency number 112 -and the network is busy, no other call will be interrupted and you won't get connected. This problem can also be solved by -adding more BTSes (for example in dual GSM 900/1800 MHz network) or by modifying -current stations to allow the use of HR channels (FR -and EFR transmission uses whole assigned time slot, while HR -(defined in GSM Phase 2) only half of it). Max data transmission speed using one TS is 9.6 kbit/sec (or 14.4 kbit/sec, -but only in some additional conditions). There are new systems allowing higher transmission speeds -(for example GPRS (Generic Packet Radio Services) or HSCSD -(High Speed Circuit Switched Data), but they achieve this using several time slots -at the same time (which decreases network capacity). Actual used TS can be checked -in test 1, in phones with HSCSD (like Nokia 6210) -use also test 8 for it... - -

VLR (Visitor Location Register) -(GSM/DCS/PCS) -
This register contains the same data as HLR, but for roaming guests -(their data are taken from their home network HLR). - - -

Back to the top
- -

[Part 1][Part 2][Part 3][Part 4][Part 5][Part 6][Part 7] -

- - -

Marcin Wiacek (WWW) -
Last modification: 5 January 2002 - - - + + + + + + + + + + NetMonitor in Nokia phones (2/7) + + + + + +

Main page

+ +NetMonitor in Nokia phones (2/7) + +

[Part 1][Part 2][Part 3][Part 4][Part 5][Part 6][Part 7] + +

+ +

+ + + +

+ + +

11. Glossary
+

+ +

Here you can find explanation to some terms, which can be found in this FAQ: + +

ACCH (Analog Control Channel) +(TDMA 800/TDMA 1900) + +

AMPS (Advanced Mobile Phone Service) +
Analogue cellular system working in 800 Mhz used, for example, in North America. + +

ASIC (Application Specific Integrated Circuit) +
Electronic chips designed for some concrete purposes + (for example, in phone it controlls communication between MCU and DSP) +They're designed and produced by the companies which use them. + +

AVCH (Analog Voice Channel) +(TDMA 800/TDMA 1900) + +

BCC (Base-station Color Code) +(GSM/DCS/PCS) +
3-bit number (from 0-7 range) used to distinguish neighbor cells of the same operator, +transmitting using BCCH in the same +FDMA channel. Such distinguish is not needed when the cells belong to different operators +(they use different channels and their BCCH are in different FDMA channels). +It is given in BSIC of each BTS (you can check it for example in +test 2). + +

BSC (Base Station Controller) +(GSM/DCS/PCS) +
It controls and supervises one or more BTSes. + +

BSIC (Base Station Identity Code +or Base transceiver Station Identity Code) +(GSM/DCS/PCS) +
Unique ID number of each BTS. If we code this value binary, first three digits (in decimal format) +are BCC and next three are NCC. These values range from 0 - 63. +BSIC values can be found among others in test 2. + +

BTS (Base Transceiver Station) +(GSM/DCS/PCS) +
This device allows communication between phones and cellular network +(many parameters, like current communication channel, distance to BTS and signal quality can be found, for example, +in test 1). + +

And here are another classes with maximum power of BTS: + +

+ + + + + +
GSM 900 GSM 1800
+320 W (55 dBm)
+160 W (52 dBm)
+80 W (49 dBm)
+40 W (46 dBm) + +-
+-
+-
+- +
+20 W (43 dBm)
+10 W (40 dBm)
+5 W (37 dBm)
+2,5 W (34 dBm) +
+ +

In Polish version of this FAQ I give many links to WWW pages with BTS lists, their descriptions, pictures (in Poland). + +

From English pages I recommend www.geckobeach.com/cellular/cellpixs/cellid.htm +site - it's about networks and BTSes in North America. + +

Another links connected with it: + +

http://go.to/nokia.info - photos of BTSes
www.club.cz/nokia.monitor/ +- BTSes bases for Czech networks

+ + +

C1 (path loss-criterium) +(GSM/DCS/PCS) +
This is a parameter (ranging from -99 to 99 dBm) calculated by the phone to decide which cells to use +(it uses the cell only if its C1 is positive). This value is based on: + +

RX +
Strength of signal received in BCCH channel. If it is equal or less than +RxLevAm, the phone searches for next +BCCH channel. It is shown in +test 1 (for current channel) +and also in test 3, test 4 +and test 5 +(for neighbor channels). The amount of measurements of the quality of transmission with BCCH channels +in neighbor cells is given in test 62
RxLevAm (Rx Level Access minimum) +
Min. level of the received signal (usually from -100 dBm to -110 dBm) needed by the phone to use particular cell.
MSTxPwr +
Max power, which can be transmitted by phone to get access to +RACH channel (i.e. max power allowed by current cell). +Actually, it is lower in towns (where cells are small) and higher outside them. +
MSMaxTxPwr +
Max permissible transmission power of the phone (its classes are described in +TX description).

+ +

It is calculated using following formula: +C1 = (RX - RxLevAm - MAX ( ( MSTxPwr +- MSMaxTxPwr ), 0) ) , where MAX(x,y) is obviously a mathematical +function giving the bigger one of the discussed numbers. +The phone shows C1 value in test 1 (for current channel) and in +test 3, test 4 +and test 5 +(for neighbor channels). + +

C2 (cell-reselection criterion) +(GSM/DCS/PCS) +
This parameter (-99 to 99 dBm) is calculated with following formula: +C2 = C1 + Cell reselect +offset - Temporary offset +* H (Penalty time - T). +If this value for some other cell (C2 for +neighbor channels can be found in test 3, +test 4 and +test 5) is higher than this value for current cell +(shown in test 1 and test 3) +for a period of time longer than 5 seconds, the phone switches cells. There are two exceptions to the rule: + +

if the new cell is located on different Location Area (this parameter for current cell can be checked in +test 11), C2 for this cell must be (during more than 5 seconds) +higher than C2+CELL_RESELECT_HYSTERESIS for old cell (where CELL_RESELECT_HYSTERESIS is a +special parameter sent in BCCH channel).
if the phone switched cells during last 15 seconds, C2 for a new cell must be higher at least 5 dBm from +C2 value of the old cell. +

+ +

H(x) function for currently not used cells is 0 (if x<0) or 1 (if x>=0). For current cell H(x) is always equal 0. +
By a skillful manipulation of this parameter (through CELL_RESELECT_HYSTERESIS), operators can direct +connections to specific cells (thus lightening load of the network). + +

CDMA (Code Division Multiple Access; also known as IS-95) +
One of the newer digital technologies in 800 or 1900 Mhz. Used in North America, Australia and some southeastern Asian countries +(e.g. Hong Kong and South Korea). It doesn't divide the radio frequency +spectrum into separate user channels by frequency slices or time slots, but +separates users by assigning them digital codes within the same broad spectrum. + +

DCCH (Digital Control Channel) +(TDMA 800/TDMA 1900) + +

DCS (Digital Cellular System) +
Cellular communication system working in 1800 MHz frequency band +(currently more often called GSM 1800) a changed version of GSM (900 MHz) system. +Its new features allowed to increase network capacity (thats why this system is used in urban areas with huge number +of subscribers) at the cost of thick net of the base stations (BTSes) +and to provide roaming within one country. GSM 1800 has different channel numbers +(see test 17), different phone +(see RX description) and BTSes +transmission power and also different max speed of the user, at which he can use his phone +(250 km/h in GSM and 130 km/h in DCS). + +

DSP (Digital Signal Processor) +
Signal processor (digital signals processing chip - controls radio interface and speech coding/decoding). +Its version can be checked in test 88. + +

DTCH (Digital Traffic Channel) +(TDMA 800/TDMA 1900) + +

DTX (Discontinous Transmission Exchange) +
Some phones and networks "care" ;-) about battery life using so called discontinuous transmission (DTX), +which turns off phones transmitter when we dont talk (but for example - listen to the calling party). +During that period the phone generates a so called comfortable :-) noise, because if our interlocutor heard the silence, +he could think that the connection was broken. + +

(GSM/DCS/PCS): +
DTX must be supported by the phone (Nokia does - see +test 78) and BTS - you can check and +(sometimes) change this in test 12 and +test 13. + +

FDMA (Frequency Division Multiple Access) +(GSM/DCS/PCS) +
This name means multiaccess on frequency field: transmission proceeds on different frequencies at the same time +(this is a "full duplex" connection): there is a down-link from BTS to the phone and +up-link - from the phone to BTS (this is called "up" and "down" because BTS +antennas are usually higher than phone ones, so the signal from BTS to the phone +really must go down (and vice versa)). + +

Frequency hopping (channel hopping) +(GSM/DCS/PCS) +
During connection your phone can continuously change used frequency (used channel) in communication with cell. +It's used, when some channel is still troubled - without channel hopping +communication with phone could not be possible, with it it's - only this +part of transmition, which is made on this frequency, is lost (so, if gives less number of +signal loss, but doesn't change sound quality - methods of coding it are always +the same). You can check (during a call) if your phone uses this function in +test 1. test 12 informs +if it is allowed by the cell (these values are updated only during a call). Channel hopping requires +Hopping Sequence Number (frenquencies are changed according to known for phone and network sequence) +- see test 2. + +

GSM (Global System for Mobile Communication) +
Cellular telecommunication system working at 900 MHz. It also has a 1800 MHz (DCS) and +1900 MHz (PCS) version. + +

HLR (Home Location Register) +(GSM/DCS/PCS) +
Network register containing information about subscribers (i.e. about their subscribed services, +tariff, last network they were logged in, etc.). + +

IMEI (International Mobile Equipment Identification code) +(GSM/DCS/PCS) +
Unique 15-digit identification number of every GSM phone on the world. It can be checked using *#06# code +(all phones) or in service menu (Nokia), which can be activated by typing a code *#WAR0ANTY# or +*#WARRANTY# (Nokia 6130). In Nokia 3110 after entering service menu (*#WAR0ANTY#) +you have to additionally enter a code 9268. IMEI contains information about the manufacturer, +place of production and serial number (check www.tele-servizi.com/janus/texts/imei.txt +for such list for Motorola phones, +here is my list for Nokia phones). +Operators can restrict network access for particular phones for example the stolen ones +(identified using IMEI number). Different operators can exchange such lists too. + +

IMSI (International Mobile Subscriber Identify) +(GSM/DCS/PCS) +
Unique (max 15-digit) number given to the phone: + +

first three digits are MCC
next three digits are MNC
the rest is a unique number

+ +

IMSI attach +(GSM/DCS/PCS) +
It is a procedure executed after each power on. The phone informs network that it is active (and is ready for communication +- receiving waiting SMS, etc.) and then it receives the IMSI number. +The counter connected with IMSI attach is located in test 64, +test 7 informs whether this is allowed by the current cell. + +

IMSI detach +(GSM/DCS/PCS) +
The phone informs network that it is going to switch off and the communication wont be possible +(its IMSI expires). The counter connected with IMSI detach is located in +test 64. test 7 +informs whether this is allowed by the current cell. + +

Location Update +(GSM/DCS/PCS) +
Every GSM phone periodically informs network about its current location. +This function is called Location Update. It is executed after changing Location Area (phone makes +it "intelligent" - when it's moved out of network coverage and the logs again to the network, makes Location Update +only when current BTS has different LAC than previous one before losing the signal) or +PLMN (after leaving the range of one network and trying to log in to another). +Then information about Location Update is transferred to a new MSC/VLR, +which in turn passes this information to HLR. When the phone works in new +MSC/VLR, HLR doesnt identify the user by +the number received from old MSC/VLR anymore. Location Update +has a couple of varieties: PLU, IMSI attach and IMSI detach +(they're distinquished in test 64). Current Location Area code can be checked in +test 11. + +

MCU (Master Control Unit processor) +
Main processor in phone. + +

MSC (Mobile Switching Center) +(GSM/DCS/PCS) +
Part of the system responsible for communication between subscribers and other users (also from other networks). + +

NCC (National Color Code or Network Color Code) +(GSM/DCS/PCS) +
3-bit number (from 0-7 range) used to differentiate cells of the operators from different countries +(for example near the border, where the phone is in range of several different networks) transmitting using +BCCH in the same FDMA channel. This number is constant +within PLMN. It is given in BSIC of every BTS +(you can check it in test 2). + +

PLMN (Public Land Mobile Network) +(GSM/DCS/PCS) +
Area covered by one operator (one network). After changing this area, the phone executes +Location Update. + +

Coverage maps of different operators worldwide can be found at www.subcam.freeserve.co.uk/mark/orange/ora.html.

+ +

PLU (Periodic Location Update) +(GSM/DCS/PCS) +
The phone informs network, on which country area (in the range of which cells) it is located. +This procedure is executed periodically (depending on the network, for example in polish +Era GSM and +Plus GSM networks every 3rd hour, in +Idea every 2th hour) +- this can be checked in test 10. This period is counted from the +last contact with network (the counter doesnt stop even if the phone loses network signal!) from the last call, sending/receiving +SMS, requesting some services (for example enabling call diverting), because the network is then informed about phones +location (but this is not registered in test 64). +The counter connected with PLU is in test 64. + +

TCH (Traffic Channels) +(GSM/DCS/PCS) +
Two way user data (computer data or digitized voice) channels. They can be divided to: + +

+HR (Half Rate Traffic): max data transfer rate is 6.5 kbit/sec (introduced in +GSM phase 2). HR channels offer worse sound quality but also longer phone standby time (even up to 30%), +because the phone using HR uses less power. The main advantage of this kind of channels is that they +enable the network to double its capacity (the number of subscribers able to make a call at the same time see +TS parameter description for more details) or to double the max range of the +BTS. Using these channels must be allowed and supported by the network (this can be +checked in test 7) and the phone. Activation code is +*HRC0#, deactivation code is #HRC0#. Unfortunately, not all Nokia phones accept these codes +(the phone should reset itself after entering them) in older models they're not supported, in never they're deactivated, when +the phone is directed to countries with networks, which doesn't support it. +Interesting fact is that in Nokia 6110 (firmware 5.24) you can decide whether the phone can use this channel or not by modifying +following EEPROM memory cells values: + + + + + + + + + + + + + +
enabling disabling
cell 0070 value for 78 +
cell 011F value for 84 cell 0070 value for 70 +
cell 011F value for 7C
+
+FR (Full Rate Traffic):transmission at 13 kbit/sec, coding using +LPC-RPE (Linear Prediction Coding with Regular Pulse Excitation) algorithm
+EFR (Enhanced Full Rate): +13 kbit/sek, coding algorithm different than in FR (ASELP (AlgebraicCode Excitation Linear Prediction) +created by Nokia and Sherbrooke University; recognized as an industrial standard for +GSM). EFR provides better sound quality at the same data transmission rate (and up to 5% +faster battery drain compared to FR). This mode can be enabled using +*EFR0# code (the phone then tries to use TCH channels in following order: EFR, FR, +(HR)) and disabled with #EFR0# (order: FR, (HR)). These codes may be not recognized +by some models (for example 6110 with some firmware versions) - +if your phone accepts them, it should reset itself right after typing them +(if this doesnt happen, you wont be able to enable/disable EFR using a keyboard code). +This channel is not supported in all older models (for example, 2110). +The type of channel used by your phone can be checked only during connection. +

+ +

When you network doesn't support one of these channel and phone recognizes its activation code, you may see +"Not ready" message. + +

You can check this in test 1. +The sequence of TCH channels can be freely set using some of the service programs +(for example WinTesla in Software/Product Profile menu) - it can be only possibility to enable HR channel in phone. + +

TDMA (Time Division Multiple Access) +(GSM/DCS/PCS) +
This means multiaccess in time: several phones can transmit signal (either digitized voice or computer data) in the +same time on the same channel (its number can be checked in test 1) +actually, this period of time is divided into very small parts (see TS description), +invisible for us, so we can assume it happens simultaneously). + +

TMSI (Temporary Mobile Subscriber Identity): +(GSM/DCS/PCS) +
During signalization procedures encrypted on radio channel +(for example, during location update) this number is assigned by +MSC to phone. In the moment, when network wants to contact +with concrete phone and transmission on radio channel is not encrypted, it's send +instead of IMSI and allows phone to indentify, that concrete +call concern on it. It doesn't have global meaning +and it's structure is definited by network administrator. Actual TMSI +you can check in test 10. + +

TS (Time Slot) +
Each radio channel used in communication between phone and +BTS is divided into 8 parts (called TS - time slots). If in all BTSes +(available for your phone) all time slots are in use, you won't be able to make/receive a call and you'll get a 'Network busy' +message (information about reason of connection failure is given among others in +test 39). Unfortunately, each type of connection has the same priority in +networks not supporting GSM Phase 2+ (it isn't available in older GSM Phases) - so if you want to dial emergency number 112 +and the network is busy, no other call will be interrupted and you won't get connected. This problem can also be solved by +adding more BTSes (for example in dual GSM 900/1800 MHz network) or by modifying +current stations to allow the use of HR channels (FR +and EFR transmission uses whole assigned time slot, while HR +(defined in GSM Phase 2) only half of it). Max data transmission speed using one TS is 9.6 kbit/sec (or 14.4 kbit/sec, +but only in some additional conditions). There are new systems allowing higher transmission speeds +(for example GPRS (Generic Packet Radio Services) or HSCSD +(High Speed Circuit Switched Data), but they achieve this using several time slots +at the same time (which decreases network capacity). Actual used TS can be checked +in test 1, in phones with HSCSD (like Nokia 6210) +use also test 8 for it... + +

VLR (Visitor Location Register) +(GSM/DCS/PCS) +
This register contains the same data as HLR, but for roaming guests +(their data are taken from their home network HLR). + + +

Back to the top
+ +

[Part 1][Part 2][Part 3][Part 4][Part 5][Part 6][Part 7] +

+ + +

Marcin Wiacek (WWW) +
Last modification: 10 March 2002 + + +

GSM 900	GSM 1800
-320 W (55 dBm) -160 W (52 dBm) -80 W (49 dBm) -40 W (46 dBm) -	-- -- -- -- -
-20 W (43 dBm) -10 W (40 dBm) -5 W (37 dBm) -2,5 W (34 dBm) -

enabling	disabling
cell 0070 value for 78 - cell 011F value for 84	cell 0070 value for 70 - cell 011F value for 7C

GSM 900	GSM 1800
+320 W (55 dBm) +160 W (52 dBm) +80 W (49 dBm) +40 W (46 dBm) +	+- +- +- +- +
+20 W (43 dBm) +10 W (40 dBm) +5 W (37 dBm) +2,5 W (34 dBm) +

enabling	disabling
cell 0070 value for 78 + cell 011F value for 84	cell 0070 value for 70 + cell 011F value for 7C