UTLS SERVER v1.7.0 (first draft)

CHAPTER 1 Differents modes Introduction a- NRIP server b- Direct IP server c- Mirror mode Installation

CHAPTER 2 Configuring the server a- Available informations b- Serial ports configuration c- Configuration of the connection to NTRIP caster d- DIRECT IP configuration e- Terminal tab f- Mirror mode

Appendix Appendix A - Considerations on the FIREWALL. Appendix B - Network configuration. Appendix C - Configuration Scripts Appendix D – routerCFG

INTRODUCTION : UTLS SERVER software is intended for the retransmission of GPS corrections over Internet. It was written for MICROSOFT. NET framework 2.0 and in fact requires this one to be able to works. Its development was made during tests that I carried out CSHARP 2.0. Estimating that UtlsServer makes several improvements in the diffusion of GPS corrections via Internet… And as any sorrow wages deserve… These improvements are : - possibility of using a dynamic IP (majority of ADSL connections) - possibility to broadcast GPS corrections without NTRIP protocol. - Remote station configurtion via internet (using UTLS CLIENT) - use of moving base station using the mirror mode. And many others…

1- Differents operating mode : a- NTRIP server . NTRIP is a protocol allowing the diffusion of GPS corrections, based on HTTP 1.1 and using TCP/IP. The format of corrections (CMR, RTCM 2.x, RTCM 3.x…) do not import because NTRIP is only the vector of those. A NTRIP system thus comprises customers, waiters and a casters.

The server send the corrections to the CASTER which redistributes them to the various clients. In single base mode, the customers must select the reference in a list which is transmitted by the CASTER (source table). Other mode exist based on same architecture (VRS, FKP) but are rather reserved for national networks implementing a large number of references stations.

b- DIRECT IP server. In this mode, there is no CASTER. The customer connects himself to the server according to IP address and TCP port of this one; he cannot select a set of corrections.

The biggest advantage of this solution is that it is simple to implement and reduces the “latency considerably”. c- Mirror mode If in direct IP mode the reference station is localised near the server (length of RS232 cable) in mirror mode the reference station is itinerant and comes to connect itself to the server. It is then seen by the client like a direct IP station.

This mode is perfect for nonpermanent installations or when one must work in mode RTK at a too long distance from a traditional server.

2- Server configuration : The software is separate on various pages which give you an access to various functions. The first of these pages gives you certain numbers information on the statute of the server. The server has two input channels via serial ports. What makes it possible to connect two GPS receivers generating two different types of corrections (RTCM and CMR or code and phase) or only one receiver which generates two types of corrections on two serial ports, For example here configuration currently in service at home:

Connection to the COM 1 of the PC will be thus the channel 1 of the server and that of the COM 2 channel 2. This enables me to broadcast via Internet two different types of corrections with the same station. When I need some (work with more than 30 kms of my residence in RTK) I bring into service the mirror mode.

Installation : After having downloaded UtlsServer the following icon must be present in the directory where this one was saved:

Simply to click on this one to start the installation procedure. Read this carrefully then click on « Next »

Read this in the same way and click on “I Agree” if you are in agreement with the licence terms. To click on “Cancel” means that you do not agree with the licence terms and will exit of the installation process.

If the .NET Framework is not installed or if your version of this one is not the required one, a dialog box similar to this one must appear. If the .NET Framework is not present or is too old on your machine click “Yes” to install it. Click “No” if you version is newer.

The following window will keep you informed of the installation progess.

Click on “Finish” and check or uncheck the box “run UtlsServer” according to what you want to do. Nota: If you are proceeding to a version upgrade of UTLSSERVER and if you want to find back all the parameters previously define, you will have to make a backup of *.CSV and *.INI files located in the installation folder of UtlsCaster.

a- Available informations This page makes it possible to know the statute of the server at the moment T as well as the history of this one since it was started.

In this page you will find all information necessary to the administration of the server : - “Server running since”: indicate since when the server is running. - “Last email send”: post the last automatic sending of Email. This relates to those which activated the automatic option of sending Email. - “Serial channel 1” indicates the serial port status and the reception of data on this port. - “Caster 1 “indicates the statute of the reference of data towards the CASTER. - “Direct IP ch.1: “ if direct IP channels are open,indicates how many clients are connected. - The log window memorizes all the events which have occurred on the server. - “Record log file”, generates a log file with information of the log window. - “Autostart” automatically starts the waiter with the last parameters. - “Autorun when Windows started” carries out UTLS SERVER with the starting of WINDOWS. Nota : For an automatic starting with the launching of WINDOWS the two preceding options must be validated. The button “Save cfg” makes it possible to safeguard the configuration of the server. This is also done automatically when leaving this one (button “Exit”). A click on « System info. » button will display a boxes with information about the use of the CPU and the bandwith.

System informations

b- Serial ports configuration.

This tab makes it possible to configure the two serial ports or input channels of your server. As it should be baudrate must be in accordance with those of GPS receiver. It is necessary to close the serial port to change the parameters. If your station GPS allows it (emission of two types of corrections on two serial ports), the standard configuration is to use channel 1 in entry of corrections CMR and channel 2 for corrections type RTCM 1/3/9. You can also use two different receivers. The scroll bars enable you to check serial port activity.

c- Configuration of the connection to NRTIP CASTER. This tab makes it possible to configure one or two connections towards one or two NTRIP CASTER. In this case the customers do not connect themselves directly to the server but to the CASTER which can be seen like a distributor of corrections.

The fields IP, Port, MOUNT Point and Password must be provided to you by the administrator of the CASTER to which you will connect yourselves. It can happen that connection to the CASTER is lost for various unmanaged reasons to UTLS SERVER In this case UTLS SERVER will carry out a number of attempts at reconnections equal to what is in the fields “max retry” while letting run out a time between each attempt equal to the fields “reconnect after”. You can redirect towards each CASTER the data resulting from the channel series 1, 2 or both at the same time. A possible configuration is to redirect the same data towards two different CASTER so that in the event of loss of a CASTER the data are always available on the second. Or to redirect each channel towards the same CASTER but on two different mount points.

d- DIRECT IP configuration. In this configuration the customers connect themselves directly to UTLS SERVER without passing by a CASTER. This thus requires that they are informed of your IP address and the port on which they can be connected. If you are connected to Internet via an ADSL connection there are strong chances that your IP addresses is of the dynamic type. I.e. that your IP address change every day and at each connection. This in opposition to the fixed IP addresses which are delivered at the subscription by your provider. In order to avoid this limitation which would prevent the customers from being connected to your server because your IP address changes every day and that they do not have any means of knowing the new address; UTLS SERVER can test your address IP regularly and send an email to a list of recipients (customers) who do not have any more that to change the address IP on which they want to be connected to get corrections the port remaining always the same one. Nota : for the moment only TCP mode is possible, the UDP should be available soon.

Local panel “information” gives you informations on your connection (IP addresses.). If you are in dynamic IP it is necessary you to notch the box “Dynamic IP” and if you want to warn your subscribers of the change of IP, the box “Send email if changed”. The configuration of the sending of email is done by clicking on the button “Email cfg” and gives access to the window “Email cfg”. It is enough to fill the fields of this dialogue box and to supplement the list of the recipients. Standard smtp port is the 25 but AOL uses the 587. All other information have to be obtained with your access provider or via a rapid seeks on Internet (http://www.arobase.org/adresses/serveurs.htm).

The configuration of DIRECT IP channels can be made only if the serial port channel associated is open. The field “Listen on port “ corresponds to the port on which will come to connect the clients. It is better to use port 2101 dedicated to the GPS but in certain cases port 8080 can be used. The max number of users is to be configured according to the band-width of your connection. It represents the maximum number of simultaneous users of the channel. Caution: an ADSL connection of 8 Mb offers only 1M upload and may be less according to your provider. The check box “Allow incomming commands” authorizes or not the taking into account of remote configuration commands to theGPS receiver, if this one can accept it. All the professional receivers can be configured via remote controls and thus if this box is validated it will be possible for you to reconfigure your receiver from the field (use of UTLS Client). Clicking on “START” will starts DIRECT IP service. The « HTTP SERVER » panel allow you to configure and start the embeded http server. This one is always awaiting connection on IP port 80 and will display informations about DIP server and allow a remote reset of the server from any internet navigator (Internet explorer or ....).

To configure this option just set a name to the server and a username / password. Then check the « Enable box ». You can now access to the server from any place and reset this one from the field if necessary.

Http page displayed e- Tab TERMINAL :

This tab makes it possible to check what is send on the selected channel or to send configuration commands to the receiver. The button “Clr” makes it possible to erase the terminal windows. Clicking "SendScript » button allow to send a configuration script to the receiver (see Appendix C). A click on this button to select the script to send.

A progress bar will show you the state of the script sends while echo commands sent appear in the terminal window. With the button "Config.Soft » you can define a shortcut to an external configuration software. At first click on it, it will be proposed to define wich external configuration software is used. Then the button will take the name of the program and to each new click on this button will see the external configuration software to be launched.

f- Mirror mode In GPRS, connections mobile to mobile are not possible, to be clear a mobile GPRS cannot be configured as a server. This mode thus offers the possibility of stage to this disadvantage. My reference station send its corrections on an IP address (fixed or not, to see MailConfig) and a TCP port. And any customer who connects himself on these same ip address and port, receives the corrections from that station.

In this mode, the distance between the station and the server is irrelevant, as well as the distance between the mobile and server. Only the distance between mobile and ref. station is significant and must be less than the maximum baseline allowed by your system. The configuration is very easy and require only to define wich TCP port will be used and the maximum of simultaneous clients. Then the following law will applied « first connected is the base station ». In fact all data received from the first are immediately resend to all other clients.

g- « About » tab.

In its downoaded version UtlsServer is in evaluation version and its use limited to 1 hour. uninterrupted. Before registering UtlsServer take care that your Internet navigator accepts cookies. After payment of the licence the button “Register now…” will be disabled and the licence full (operation not limited to 1 hour). The payment of the licence is done only in secure mode using PAYPAL http://www.paypal.fr/fr.

Appendix A Considerations on the FIREWALL.

For the data transmission towards a casters (NTRIP) no configuration of the FIREWALL is necessary. On the other hand in modes mirror or Direct IP, your PC must to be able to accept connections entering and if you are protected by a FIREWALL what is strongly recommended, this one should be configured. But the types of FIREWALL being rather numerous and their mode of configuration as various as varied it was impossible to integrate all the firewall in UTLS SERVER. That those which use WINDOWS XP (2000) and its integrated FIREWALL delight, no configuration of this one is necessary UTLS SERVER takes care of all. They will be able at most to check the good configuration of this one while going in the “Security center ” of WINDOWS XP.

Then in “Managing the security parameters” to click on “Windows firewall” and to check that the rules were indeed added for UTLS SERVER. It can also prove to be necessary to notch the box to authorize the exceptions. While clicking on modifying you will be able to see that the open ports are well those which you selected in UTLS SERVER. There are as many rules as of ports open and thus three to the maximum (2 DIP and a mirror). For all the others it will be necessary for you to configure your FIREWALL by hand. There are no fears to have because that is not so complicated. Two cases are all the same to consider:

1-/ You are behind a corporate network: There is not many solutions and it is necessary to see with your network administrator… But this one will undoubtedly be made a pleasure of opening the ports to you and of redirecting them towards the machine where you will have installed UTLS SERVER. 2-/ You want to use your ADSL connection and your PC as server. You will find on Internet some excellent tutorials on NAT configuration for your router of which here an http://perso.orange.fr/jmrreb/st510v4.htm example for the modems SPEED TOUCH. You should just know the local address of the machine on which UTLS SERVER is installed as well as the ports that you chose.

In the example above all the requests for entering connections on ports 2101 and 2102 are redirected towards these same ports on the 10.0.0.2 machine which is that where UTLS SERVER is installed.

Appendix B Network configuration.

An important parameter of your network is the MTU (Maximum Transfer Units). Indeed this parameter will define the maximum size of TCP packets forwarding on the network and thus the performance of this one. A rapid approach authorizes with saying that more the MTU is large more the network will be fast. It is a little simplistic but not far from the truth knowing that the maximum size of a package in TCP cannot exceed 1500 bytes. This value is largely sufficient for what we want to do and corresponds to approximately 3 seconds of data in RTCM 2.3 and much more in CMR. Always with regard to the size of TCP packets and as Internet was not made for real time applications it is necessary to take into account the fact that smaller is a packet more it is transferred quickly on the network. Problem which one can summarized by: More the packet is large and better is the performance of the network and more this same packet is small more it goes quickly on the network. It thus the good compromise should be found. The default adjustment of UtlsServer are correct for the majority of the networks but can require to be to adjusted in certain cases. The first parameter to be adjusted will be the MTU, for that I advise you to go to make a turn on the excellent http://www.dslvalley.com/dossiers/mtu/mtu.php website where you will find all information necessary knowing that I recommend to apply the highest possible value (1500). The second parameter is the size of the packet which UtlsServer generates. This one can be adjusted easily by opening the file “server.ini” and by modifying the last values of lines 3 and 4.

True,False,True 1,4,3,0,True,True pwd,LPS1,2101,81.255.195.106,30,5,0,False,150 5,30,,,,,-1,False,150 True,0,False 2101,1,0,False,False 2102,1,0,False,False

Typically these values will have slightly lower than the size of smallest correction packet to be generated the by the receiver. Here some indicative values: CMR/CMR+ -->250 RTCM 2.1 --> 150 RTCM 2.3 -->400 Another parameter which it can be interesting to modify is the rate of repetition of TCP packet. TCP/IP at definite summer so as to guarantee the integrity of the transmitted message and to summarize it should once more be remembered that Internet was not designed for real times applications but for soldiers (that the order to send the bomb arrives with 3 seconds of time does not have importance but only the position where it must fall is false is more awkward…). By WINDOWS default configuration 5 times a package TCP is configured to repeat if this one is badly received by the recipient. What for us is without interest since the lifespan of a package of corrections is one second. One can easily modify this by publishing in the base of register the TcpMaxDataRetransmissions key and by fixing this value to 1.

Appendix C Configuration Scripts

Since version 1.5, UtlsServer allow you to define your own configuration scripts for your GPS receivers (base station) if this one accept configuration commands in text format. This functionality can be accessed from the terminal tab, "SendScript" button. You will have to check with the manufacturer of your receiver to determine if he is compatible with the commands in text format and the list of commands required to configure your reference station.

Script concept in UtlsServer: Clicking "SendScript » button of the Terminal tab lets you send a command script to the receiver without any interaction on it. It is a fixed script as defined by the manufacturer of your equipment. Either something like this for a receiver ASHTECH. $PASHS,RST $PASHQ,RID $PASHS,BEEP,OFF $PASHS,ANT,0.045,0.0,0.0,0.0,0.0 $PASHS,RTC,AUT,Y $P.......... It is a suite of simple commands who can be sent over the serial link to configure the receiver. We understand from reading this small text file that all command syntax are preceded by the word $PASHS then the command (RST to a reset receiver) for a receiver ASHTECH, other receivers using another set of controls. If you are able to transfer a file as it is of this type, it may be worthwhile to add a little interactivity for the user (modifying antenna elevation mask , for example). That is what UtlsServer allows you using its own commands set. The latter are presented in this form: $UTCMD,PARAM,Station #,Station Number (0 to 1024),1#4 $UTCMD,PSE,500

The previous command will display this dialog box

How to create a script. The easiest way is to use WINDOWS NOTEPAD and modify an existing script or create one from scratch. Sets orders varies widely depending on each hardware manufacturer, I advise you to ask your supplier's for the command set that suits your hardware.

Editing a command file with NOTEPAD

Utilsea commands set. These are in numberof two : $ UTCMD, PSE: $ UTCMD, PSE, x Tells UtlsServer make a break of x milliseconds after sending commands. This command can be found several times in the script with different values depending on the response time of the receiver. Ex: $ UTCMD, PSE, 500 Will take a break of 500mS after sending each commands. PARAM: $ UTCMD, PARAM, boxtitle, ParamName, yyyyy # n! B! D # ............................... vv This has the effect of displaying a dialog box that allows the user to enter some parameters. The maximum number of text boxes that can be open simultaneously is 7 with 2 optional lists boxes

Dialog box title A dialog box is defined thus: A title of dialog (here in red)

Some labels

Text boxes to the number of 7 maximum and usually associated with a label.

$UTCMD,PARAM,Elevation Mask,Elevation Mask (0 to 90°),5#3 1

2

3

1 - The title of the dialog box 2 - The title of the input field 3-value 5 is what is displayed by default in the input area. The # character and value 3 indicates that the value entered in the text box comes in the field No. 3 of the GPS receiver command line.

For example here with an ASHTECH receiver : $PASHS,ELM,5 Field N°1 = $PASHS Field n°2 = ELM Field N°3 = 5 ' this field will be set with the inputed value

Note: field separator must be the comma char. One can rehearse up to 7 times the overall title, default # # fields. If you want to add a list box to get something like this:

Just after the number of fields (# x) add the character ! (exclamatio mark) And always separated by the same character values predefined and end with the character # and the number of fields that will fit the selected value. $UTCMD,PARAM,Ref. Pos,Lat.(DDMM.mmmmmm),4717.543212#3!N!S#4, Here adding "!N!S # 4" will display a listbox after the text box. A sample of configuration script an ASHTECH receiver: $UTCMD,PSE,500 $PASHS,RST $PASHQ,RID $PASHS,BEEP,OFF $PASHS,ANT,0.045,0.0,0.0,0.0,0.0 $PASHS,RTC,AUT,Y $UTCMD,PARAM,Elevation Mask,Elevation Mask (0 to 90°),5#3 $PASHS,ELM,5 $PASHS,CPD,MTP,2 $PASHS,CPD,MOD,BAS $PASHS,CPD,AFP $UTCMD,PARAM,Ref. Pos,Lat.(DDMM.mmmmmm),4717.543212#3!N!S#4,Long.(DDDMM.mmmmm),00130.548963#5 !W!E#6,Height,+127.235#7 $PASHS,POS,4717.543212,N,00130.548963,W,+127.235 $UTCMD,PARAM,Station #,Station Number (0 to 1024),1#4 $PASHS,RTC,STI,1 $PASHS,SAV,Y

In yellow Utilsea commands and in blue ASHTECH proprietary commands.

Appendix C RouterCFG since the version 1.7 UtlsServer package include a tools allowing an easy configuration of your modem router. This tools allow the necessary opening of TCP port to run UtlsServer.

This tools is accessible from the « Start » menu UtlsServer folder. At the beginning RouterCFG is looking for your modem router and then display information about this one.

Your modem/router must be compliant with UPNP norme to get RouterCFG working. When it's done you have just to click on « List rules » button to diplay the rules already defined in your router.

To remove a rules, select this one and then click on « Remove » button. Rmks : you are authorized to remove only the rules defined for the computer on wich you run RoutersCFG. To add a rules a click on « Add » button will show the following dialog boxe :

You have just to fill the fields port and protocol in accordance with what was selected in UtlsServer for each DIP channel.

If you are using the http server do not forget to add a rules for the port 80 with TCP protocol. Rmks : the rules defined using UPNP are not stored in router memory and have to be redefined after a power cycle or a reset of your modem.

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