Topex TOPEX MobiLink IP, User Manual

Page 1: ...TOPEX MobiLinkIP Preliminary Manual TOPEX MobiLink IP 2G 3G VoIP 2 Mobile Gateway With Web Interface User Manual 2009 TOPEX S A 4 021 408 39 00 http www topex ro Page 1 of 80 ...

Page 2: ...ating system kernel The other flash circuit is for the applications which can be easily updated upgraded or enhanced Easy Firmware Updating Automatic update process using the web configuration interface Highly versatile It can be used together with an IP PBX for SIP subscribers It may be also used as standalone with a soft phone or hardware IP phone Multiple mobile networks and standards supported...

Page 3: ...be disposed separately as sorted waste At the end of its life it will be given to a specialized recycle firm Please do not dispose of the TOPEX product as unsorted waste household waste recycle it to protect the environment Separate the packages according to waste disposal options and sort it for recycling For supplementary information contact us to Phone 4021 408 39 00 or www topex ro TOPEX S A 4...

Page 4: ...l antennas 21 Power up 23 Status indicators 23 CONFIGURATION 24 Required conditions for configuration 24 Using the web interface 24 NETWORK 32 Status 33 IP Settings 35 1 1 1Static Routes 37 Commit 39 SNTP Client 39 Mobile 41 Status 41 Settings 44 VoIP 46 Codec Settings 46 DTMF Settings 48 5 5 3 Voice Settings 48 PBX 50 Status 50 Settings 53 Register users 54 Incoming calls 55 Outgoing calls 56 PBX...

Page 5: ...TOPEX MobiLinkIP Preliminary Manual OPERATING ENVIRONMENT 74 GLOSSARY 76 Revision G firmware 1 0 1 M2P SAX edition September 2009 TOPEX S A 4 021 408 39 00 http www topex ro Page 5 of 80 ...

Page 6: ...TOPEX MobiLinkIP Preliminary Manual INTRODUCTION TOPEX S A 4 021 408 39 00 http www topex ro Page 6 of 80 ...

Page 7: ... digital MobiLink equipment allowed connections to phone terminals or PBX s located a few meters or up to 1000m away with MobiLinkIP the length of the connection becomes infinite The mobile gateway may be located anywhere in the world and still perform an interface task Support debugging and firmware upgrading can also be performed faster and from a longer distance Previous versions of the MobiLin...

Page 8: ...to be terminated through MobiLinkIP devices located at the corresponding sites The respective MobiLinkIP devices will then directs the calls to the required local GSM network with the minimum possible cost Flexible Usage MobiLinkIP can be used in several ways with an IP PBX that has SIP subscribers with hardware SIP telephones with soft phones such as the free application SJ Phone In order to ensu...

Page 9: ...tes VoIP calls which least call routing for SIP calls Power supply switching mains adapter Input 100 240V A C Output 12VD C 2A Max Power 25 W Ethernet cable for local network connection A short piece of UTP straight cable with RJ 45 connectors Antennas for mobile networks Multiband with magnetic base and 2 5 m long cable CD with User s Manual Quick Install Warranty Certificate TOPEX S A 4 021 408 ...

Page 10: ...s to all its settings Since the product is Linux based applications to enhance MobiLinkIP or to customize it according to the special needs of various clients can be quickly designed by our software developers If signing up for our technical support offer our best technical experts are available for technical queries In addition the software upgrades can be done remotely via the Internet and are f...

Page 11: ...dicate the characteristics and compliance SIGNIFICANCE OF LABELS These adhesive labels contain information about the manufacturer type model certification approval and compliance to UE and international or USA directives such as FCC The labels may include barcodes and refer to Manufacturer and product type TOPEX S A 4 021 408 39 00 http www topex ro Page 11 of 80 ...

Page 12: ...l network side and MAC WAN the Media Access Control address on the side of the external network IMEI code International Mobile Equipment Identity for SIM based equipments A unique 15 or 17 digit number such as 269751923786501 that identifies an individual mobile station to a GSM or UMTS network handset The IMEI code is on all GSM and UMTS mobile terminals commonly found in Europe Asia Africa and i...

Page 13: ...ents the WEEE Directive by banning the presence of specific hazardous substances such as lead in the products at the design phase The forbidden waste bin symbol shown on the Topex device or on its packaging indicates that this product must not be disposed of with other waste Instead it is the user s responsibility to dispose of the device by handing it over to a designated collection point for the...

Page 14: ...nformation which is NOT available through the adhesive tags Such information is related to the serial of the motherboard of the device or the software version actually running on it For this you must access the System Status page Just enter into the browser the URL for the page https 192 168 173 1 System Status The information about serial number current firmware and kernel can be found in the opt...

Page 15: ...is a unique 15 digits code number that identifies a mobile subscriber to the network If the MobiLinkIP s module detects an active SIM card it will query and display the IMSI code Since the IMSI code is related to the SIM when changing the SIM card another IMSI code is available IMEI International Mobile Equipment Identifier 15 digit number that uniquely identifies an individual mobile wireless ter...

Page 16: ...he adapter shipped with MobiLinkIP The jacks of different power supplies may fit but the polarity current voltage or regulation factor may not be compatible While the device is in operation the antennas of the MobiLinkIP unit should be at least 30 centimetres away from any human being MOUNTING HARDWARE INSTALLATION The Topex MobiLinkIP router may be mounted either horizontally by means of simply p...

Page 17: ...is needed Installing MobiLinkIP on a shelf higher up with no obstructions around ensures the best performance embedded GSM or 3G modems Take care to ensure adequate cooling of the MobiLinkIP terminal IDENTIFICATION OF CONNECTORS Topex MobiLinkIP features only two external connectors as described below On the bottom panel of the equipment they are from left to right Figure 2 Connectors of MobiLinkI...

Page 18: ...P interface Use either a 10Base T or a 100Base T connection Figure 4 Connecting the LAN cable UTP CAT5 The network cable is to be inserted with one end into the RJ 45 socket of the MobiLinkIP device labelled ETH The opposite end of the UTP cable can be inserted directly into a PC or in switches or hubs The STATUS indicator LED of the MobiLink case will light up showing physical connection and will...

Page 19: ...nnas while the MobiLinkIP device is powered CONFIGURING AND INSTALLING THE SIM CARDS The MobiLinkIP device may feature a single slot or two slots in dual SIM version for SIM cards In order for the MobiLinkIP gateway to work it must have at least one valid SIM card with subscription to the GSM or 3G voice carrier where connection is needed Configuring the SIM card s The SIM card s that is used must...

Page 20: ...button to actuate each holder Note that in case of two SIM slots the SIM holders are in a row one following another the first one from the left is SIM2 fro Mobile 2 network and the second is SIM1 for Mobile 1 network Handle with care when inserting or extracting SIM card IMPORTANT When inserting or changing the SIM card the equipment must be powered off For inserting the SIM card follow the next s...

Page 21: ...cedure for the second SIM take care to insert the SIM card correctly Connecting the external antennas To ensure a good quality of transmission and to reduce radio interference use the antennas shipped in the MobiLinkIP package These antennas were designed for the respective frequency bands multiband to allow proper connection to different mobile networks type GSM or 3G The antennas must be connect...

Page 22: ...essive force Make sure the antenna is securely screwed into the RF connectors but do NOT use a spanner or screw key which could damage the antenna connector Tighten the flange lightly by hand The antennas have vertical polarization so they should be placed in vertical or horizontal position depending of the local field condition Place the antennas on a safe stable non magnetic and flat area The he...

Page 23: ...ators may light up continuously in red orange or green color or flash to show status and data traffic The three LEDs are located on the upper right corner of the MobiLinkIP case above the two slots for SIM cards They are labelled respectively STATUS MOBILE1 1 and MOBILE 2 Figure 7 LEDs location Significance of LED indicators STATUS Shows the state of the equipment Indicates the proper power supply...

Page 24: ... you should check the basic settings to guarantee it will work in your environment for instance it may be required to change the default IP address and subnet mask Required conditions for configuration To be able to configure the MobiLinkIP device one must be connected to a LAN Ethernet 10Mb s or 100 Mb s and have access to a computer that is connected to the same network via router or switch Alte...

Page 25: ...mplest way is to set the network adapter to get its IP address automatically from the DHCP server of the local network where the MobiLinkIP unit is connected The server will provide the PC or netbook with the correct IP address DNS and Gateway This only works if you local network is of the class 192 168 xxx yyy compatible with the default IP address of MobiLink IP Manual settings As an alternative...

Page 26: ...DNS server fields may be lefty empty In the status bar at the bottom of the screen the link icon should be blinking and a message will show up MobiLinkIP is now connected Note When a Proxy Server is used for the local network set an exception for the Topex VoIP2Mobile because access to the MobiLink will not be possible Connecting to MobiLink Enter the IP address of the MobiLinkIP device by default...

Page 27: ...T happed if you don t follow exactly the procedure described above for instance if you continue to press RST after the three indicators have turned on in red color Note that the MobiLinkIP uses a secure web connection https instead of the usual http so one may get several warning messages for example or similar warnings mentioning Website Certified by an Unknown Authority Click Yes OK or Accept to...

Page 28: ...ackers from capturing passwords and sensitive data which is the same security used by banks and the military or Internet Explorer shows the padlock icon only when everything on the entire webpage is encrypted But even when the browser doesn t show a padlock the https address means the data is still encrypted Other browsers such as Mozilla Firefox will also show a lock icon near the MobiLink connec...

Page 29: ...user For the administrator of the system network the default user name is admin and the password is 99admin11 Later this password may be changed using the web configuration page as described in the paragraph about Password For security reasons it is strongly recommended to change the default password with one of own choice as soon as possible Also do NOT mark the checkbox Remember my password in t...

Page 30: ...tem accessible when logging in as Administrator is MISC The Miscellaneous section was created to include different advanced settings that are not required by a normal user but may be needed for a system administrator Such settings may be TCP IP advanced networking parameters for the IP connection for instance the ICMP redirects and also the Host name to be used other settings related to the admini...

Page 31: ...located to the left and features the button Commit at the bottom On top of the web page next to the Topex logo is a Location indication which reminds the user exactly where he is on the Web interface In this example the section is Network and the subsection IP settings IP Settings for the Ethernet connection Under the Location information is Remote User which shows the name that was used for log i...

Page 32: ...reliminary Manual NETWORK This group features the pages of settings related to the local wired Ethernet network for IP routes and respectively for the NTP Client TOPEX S A 4 021 408 39 00 http www topex ro Page 32 of 80 ...

Page 33: ... is the detailed information about the Ethernet network interface of the MobiLinkIP It contains two similar groups of network parameters Adm0 Details about the real Ethernet interface including MAC physical address Internet address logical address Broadcast subnet mask MTU value metric statistics packets errors collisions mega bytes transferred for the reception RX and respectively transmission RX...

Page 34: ...table for IP Or The Static Route Display shows the current routing table of the MobiLinkIP Note that this is the Status page for network the existing static routes for the MobiLinkIP default routes gateway masquerading if used flags metric interface used etc can be seen and changes cannot be performed If needing to change the routes go to the section Routes of this page for defining and modifying ...

Page 35: ...ateways Thus the networks which are directly connected don t have the G flag but it is activated for all other routes H it is a route towards a single host instead of a network D the table entry has been generated dynamically either by a routing protocol or by an ICMP redirect message see section 3 5 M this route was modified by a dynamic routing protocol R the route was re activated following upd...

Page 36: ... 192 168 xxx yyy When changing this IP address MobiLinkIP tries to redirect the web browser to the new address automatically If it does not succeed update the configuration page by entering the new IP address in the browser such as https 192 168 173 4 in the above example and pressing the Reload button of the browser DNS Servers Select which primary and secondary servers for DNS Domain Name Servic...

Page 37: ...d here will be shown in the page Network Status Routes Set IP Routes lets one edit remove or add routes in the table shown below Static Route Definition Such a static route is a possible path from a device to its destination or to another host One must insert predefined rules of routing for the MobiLinkIP in case of appending one or several network devices such as routers behind the MobiLinkIP dev...

Page 38: ...ion IP address is the network part and which is the host part Gateway the gateway to be used enter here the IP address of the router which allows for contact between MobiLinkIP and the remote host or network Enable Each of the routes defined or edited can be individually enabled or disabled This is especially useful when configuring several mobiLinkIP devices one after another or when the configur...

Page 39: ...changed settings are saved into permanent Flash memory of the equipment The MobiLinkIP resets and when it starts again the new set of parameters will be active Warning While committing changes when resetting the MobiLinkIP or while loading a new program image the equipment will cease operation for a few seconds This means all connections voice local network etc will be interrupted but will resume ...

Page 40: ... there is no connection to the Internet it will display the default UTC date time which is begins at Jan 1 2000 and 0 00 00 When the NTP Client becomes active it shows the current UTC time This UTC time may be different from the local time of your computer In the system logs one can see the moment when the applications running on MobiLinkIP connects to the Internet and the time jumps from the defa...

Page 41: ...mobile interfaces of the equipment It also has two sections one for displaying the current state and the other for configuring the mobile modules Status Displays the state of the selected mobile interface First select the Mobile interface whose state will be shown select 1 or 2 then press Load to see the current state below for Mobile 1 TOPEX S A 4 021 408 39 00 http www topex ro Page 41 of 80 ...

Page 42: ...nt carrier PIN state of the PIN code Ready or OK is the normal state which means the SIM is active unlocked and the equipment may be used It happens when the PIN is not requested or that it is asked for the correct value has been entered so the Sim can operate If it shows ERROR it means the respective SIM is blocked because of a missing or incorrect PIN code You must disable PIN request for the su...

Page 43: ...e International Mobile Equipment Identifier is a 15 digit number that uniquely identifies an individual mobile terminal wireless device While IMSI is specific to the subscriber SIM card IMEI is specific to the equipment cellular modem of MobiLinkIP If the SIM card is missing the SIM Status window will show error in the fields PIN IMSI Signal Level Network and respectively Registration But the user...

Page 44: ...inary voice calls it is only good for the emergency services 3 The Mobile information available depends upon the actual type of the cellular module used in MobiLinkIP and upon the service provider Thus it is possible that you get less detailed information as in the following example Settings The settings for the two Mobile interfaces One can edit the parameters for each of the two cellular interfa...

Page 45: ...the Default button located at the bottom of the page to restore the default level for both input and or output Definition of RX and TX In this page for Mobile Settings RX is the voice path coming form the mobile network towards VoIP while TX is the reciprocal voice path which comes form VoIP towards the mobile network Note1 Don t forget to use the button Save to store the changes performed over th...

Page 46: ... receiving of ID for all the calls performed over the respective Mobile module Action The last field Action selects the action to be performed First Edit to choose the row Mobile module where settings needs to be changed Now the field name changes to Exit which should be clicked to leave the respective row of settings When finished configuring don not forget to press Save before leaving the page V...

Page 47: ...gly RTP Packet Length It lets you establish the value for packetization time in milliseconds for each codec It is usually set to 20 but it may be as long as 30 msec or as short as 5 msec Increasing the packetization time reduces the packetization overhead but increases the latency Voice VAD Enables or disables the Voice Activity Detection by default this feature is disabled Typical voice conversat...

Page 48: ...out INFO messages as digital telephone events Under the SIP protocol the INFO method would be used for carrying of mid call signaling information along the session signaling path for example to send the DTMF digits generated during a SIP session Check the box SIP Info for this way of transmitting DTMF When checking this RFC 2833 options also complete the next Parameters fields to the right payload...

Page 49: ... amplification you want from zero dB up to 24 db in 6 dB increments Definition of RX and TX In this page for VoIP voice Settings RX is the voice path going out from VoIP towards the mobile network while TX is the reciprocal voice path which comes from the mobile network towards VoIP The meaning of Tx and respectively Rx are reversed compared to the page Mobile Settings TOPEX S A 4 021 408 39 00 ht...

Page 50: ...ol management routing Status Displays the current state of the ports of the embedded phone exchange as well as the states of the calls There are two sections PBX Ports and respectively Calls In the stand by state shown above both ports are free and no info about calls is displayed since there are currently no conversations going through the MobiLinkIP TOPEX S A 4 021 408 39 00 http www topex ro Pa...

Page 51: ... the GSM interface Mobile2 The mobile number called is 0724 while the SIP user who calls in bogdan Ports 1 2 are the two Mobile ports while 261 262 are VoIP ports Direction the calls may belong to one of the directions MYVOIP SIP mobile1 mobile1 Type type of the call it may be in for incoming or out for outgoing State current status of the call alerting proceed or connected Protocol SIP for VoIP C...

Page 52: ...le call comes in via cellular interface Mobile 2 from the mobile number 0724 and goes out as an SIP call via VoIP port 262 to the extension 284 Now both mobile interfaces and both SIP ports of the MobiLinkIP are busy Next the user sees a cellular call routed with DISA function instead of Target number as was done previously A single incoming call gets in through interface Mobile 1 from the phone n...

Page 53: ...blishes the sub network of the PABX calls will be accepted from all the SIP phones from the same sub network 0 calls are accepted form any address 8 from 192 168 yyy xxx 16 from 192 168 244 xxx 32 only form a single address 192 168 244 239 in example above SIP Port number of the port used for SIP calls Here the port used for SIP is the standard 5060 but the user may change this value if the SIP PB...

Page 54: ...e specific SIP user For each user fill in the local extension number such as 346 a password used together with SIP username for SIP user registration the settings for expiration tine and NAT refresh Notice that each entry in the list of registered SIP users may be individually enabled or disabled so there can be a list with several users out of which only some are currently enabled active TOPEX S ...

Page 55: ...ination and Action to be taken First click Edit to start editing the specific row then Exit and save the settings Target the number of the local extension where the calls will be routed which are coming in through the respective Mobile interface 196 241 283 etc in the examples used DISA select No default or Yes from the drop list If choosing YES the value in the field Target doesn t matter any lon...

Page 56: ...abled The program analyses the numbering the prefix of the phone number called and routes them accordingly through one of the mobile interfaces If one of the mobile ports is disabled the respective GSM module will NOT be used for outgoing calls Use the New button to create a new rule Edit to fill the parameters for it Exit to get out of the respective row and Save to save the rules created The but...

Page 57: ...ich ones one must use this format for compatibility all the prefixes in the table must have the same number of digits The value any in the field Interface means that the respective call can be routed via any of the two modules PBX Querry Allows the sending of text commands to the phone exchange application which runs on the MobiLinkIP equipment The command help shows you all available commands TOP...

Page 58: ...TOPEX MobiLinkIP Preliminary Manual Log Settings Here one can set up for each section of the log how much information will be stored TOPEX S A 4 021 408 39 00 http www topex ro Page 58 of 80 ...

Page 59: ...thing is logged for the usage of developers SYSTEM It shows the current state of the MobiLink IP equipment and the logs also allows performing several system related operations The system configuration pages include these settings Status displays the current status of the MobiLinkIP equipment Syslog View shows the log file and allows you to save it Syslog Settings settings for the remote log Updat...

Page 60: ...pex mobililik ip 0 0 4 MJJ or topex mobiLink 1 0 1 M2P xyz The firmware can be easily updated a new version or upgraded new software features added Kernel version Operating system version such as topex system 1 0 0 MXX or topex mobilink ip 0 0 3 A in the example above The application firmware and the operating system root or kernel may be updated separately according to the requirements of the use...

Page 61: ... changes made devices and drivers detected files added or deleted communication with the modem network settings etc Correspondingly records of the kernel or of the user info debug messages info or warnings can be seen in the log The log is very helpful when troubleshooting It may be saved on a PC simply use Save As option of your browser for further examination Use the button Save and reload at th...

Page 62: ...the size of the circular buffer that temporary stores the log Update Allows one to perform an update or upgrade of the firmware running on the MobiLinkIP The webpage displays a single field Enter in Upgrading Mode No Yes As you can see the default is No to prevent accidentally going to the mode of operation Upgrade If you do want to perform a software upgrade select YES from the drop list then cli...

Page 63: ... error occurs during software update and the image file gets corrupted the equipment will restart in System mode allowing you to The Upgrade configuration page is simplified containing just a few elements MobiLinkIP is operating in System Kernel mode only There are only two pages available NETWORK and SYSTEM Network shows the state of the network you can t perform changes In System you can both se...

Page 64: ... hardware model such as M1P or M2P These are very important because you must allways load a firmware image which corresponds to the type of your equipment when you have a M2P box you must update with an image type M2P and not M1P or M2J The three letters at the end such as SAX or SCX define the software version Enter the name of the update or click Browse to search for it on the system In the exam...

Page 65: ...e with txt extension with the same name as the firmware image Using a control sum prevents the user from loading a corrupted image Open the associated text file with the control sum as shown below Open it with a text editor m such as NotePad copy the string of checksum from this file and paste it in the MobiLink IP web page in the field named Control Sum TOPEX S A 4 021 408 39 00 http www topex ro...

Page 66: ...e image in the first one while the message Updating firmware is blinking the equipment just checks the program image to be loaded against its checksum if the result of the verification is OK the MobiLinkIP device goes to the second phase where it actually loads the new firmware into its Flash memory After the loading of the new firmware is completed you you can restart the MobiLink IP equipment to...

Page 67: ... defaults by keeping the RST button pressed when you power up the equipment The button will start up the main application software running on MobiLink IP which allows it to perform as a VoIp to Mobile gateway To verify the updating of the firmware you can compare the System Status screen before and after loading the software image Before After update TOPEX S A 4 021 408 39 00 http www topex ro Pag...

Page 68: ...updating verify the upgraded firmware remember that updating the firmware on the MobiLinkIP could cause some or all of the configuration settings to be lost depending on the degree of change in the firmware Therefore it is highly recommended to save the current configuration before updating and then restore it To backup the settings perform a Save update the firmware and then load the saved settin...

Page 69: ...click the YES button and the equipment will revert to the factory default settings Following a reset it will start operating with the factory default values for all parameters During the process Updating settings please wait and a red progress bar can be seen as shown below CAUTION Use this option carefully During the process the MobiLinkIP will not be available for VoIP call routing and connectin...

Page 70: ...the same care should be exercised Note The Return to Defaults option is quite useful when incorrect settings have been performed or when the IP of the MobiLinkIP device are forgotten If not having the IP address or if having incorrect settings for iptables one won t be able to connect to the VoIP2Mobile to administer it Perform a hardware factory defaults and MobiLinkIP will revert to its original...

Page 71: ...revious settings are lost If the configuration was saved it can be loaded back to perform changes Also one should perform a Save before using Update to load a new software image since the new firmware could erase some of the settings This is especially useful when having configured many particular settings for example related to routing rules or to IP SEC tunnels it will take a long time to edit t...

Page 72: ...nary Manual Use Browse or Choose button to navigate to the location where the configuration file was saved Press Open then click Send to send the file to the MobiLinkIP TOPEX S A 4 021 408 39 00 http www topex ro Page 72 of 80 ...

Page 73: ... 2 NTP and others Features Web configuration Wired Network interface One LAN port Ethernet 10 100 base T Connector type female RJ45 Transfer speed 10 100 Mbps Max transmitter power GSM GPRS EDGE 800 900MHz 32dBm Power Class 4 GSM GPRS EDGE 1800MHz 29 dBm Power Class 1 UMTS HSDPA 2100MHz 23dBm Power Class 3 8PSK mode Class E2 only for devices fitted with 3G modules Receiver static sensitivity GSM G...

Page 74: ...kIP must NOT be used in a flammable or explosive environment or in locations where toxic or flammable gases may accumulate The equipment must be handled with care to avoid mechanical shocks and blows The MobiLinkIP should not be used in an environment with high level of EMI electromagnetic interferences that is in close proximity to high power equipment such as electric motors or heaters In additi...

Page 75: ...inary Manual When the life cycle of this device has expired and it cannot be repaired or re used dispose of it in accordance with applicable laws and legal regulations TOPEX S A 4 021 408 39 00 http www topex ro Page 75 of 80 ...

Page 76: ...nese speaking customers DNS Acronym for Domain Name System or Service an Internet service that translates domain names into IP addresses This allows the Internet hosts to use both addresses type domain name such as topex ro or linux org and addresses type IP numbers for instance 192 17 3 4 The domain name addresses are intended for human users and are automatically converted into IP numeric addres...

Page 77: ...ent by a different route across the Internet These data packets can arrive in a different order than the order they were sent in The Internet Protocol just delivers them It s up to TCP protocol Transmission Control Protocol to put the packets back in the right order Note that IP is a connectionless protocol which means that there is no continuing connection between the end points that are communic...

Page 78: ...security enhancements for WWW based commerce Web pages that use S HTTP have a URL starting with https Typically HTTP data is sent over TCP IP port 80 but HTTPS data is sent over port 443 The standard was developed for secure transactions and uses 40 bit encryption weak encryption or 128 bit strong encryption The HTTPS standard supports certificates and allows encryption digital signatures authenti...

Page 79: ...ved from a given frequency spectrum by interleaving pulses representing bits from different channels In some TDM systems successive pulses represent bits from successive channels In other systems different channels take turns using the channels for a group of successive pulse times a so called time slot such as voice channels in E1 T1 landline systems or wireless GSM systems What distinguishes coa...

Page 80: ... or transmitted in any form or by any means electronic mechanical recording or otherwise without the prior written permission of the company TOPEX S A It is certified hereby that the Topex MobiLinkIP unit is manufactured in concordance with the legal provisions concerning responsibility towards the quality of delivered products fulfils the quality parameters specified in its User s manual and is f...