OpenBTS Development Kit

Contents 1 Introduction 6 1.1 Scope and Audience......................................... 6 1.2 Disclaimers.............................................. 6 1.2.1 Errors and Future Changes................................. 6 1.2.2 Radio Interference...................................... 6 1.3 Abbreviations............................................ 6 1.4 References.............................................. 7 1.5 Contact Information......................................... 7 2 Specifications 8 2.1 Mechanical Specifications...................................... 8 2.1.1 Package Dimensions..................................... 9 2.1.2 Ventilation.......................................... 10 2.2 Environmental Specifications.................................... 10 2.3 Electrical Specifications....................................... 10 2.4 RF Specifications.......................................... 10 2.4.1 RF Output.......................................... 10 2.4.2 RF Input........................................... 11 3 BTS Operation 12 3.1 Installed Components........................................ 12 3.2 Source Code............................................. 12 3.3 Initial Power-Up Procedure..................................... 13 3.4 System Access and Control..................................... 13 3.5 Accessing the OpenBTS Console.................................. 13 2

CONTENTS 3 3.6 Safe GSM Configuration..................................... 14 3.7 Initial Testing............................................ 14

List of Figures 2.1 OpenBTS Development Kit front panel mechanical......................... 9 2.2 OpenBTS Development Kit side view mechanical.......................... 9 4

List of Tables 2.1 OpenBTS Development Kit mechanical dimensions......................... 9 2.2 OpenBTS Development Kit environmental specifications...................... 10 2.3 RF operating ranges......................................... 11 5

Chapter 1 Introduction 1.1 Scope and Audience This document describes the physical specifications and initial installation of the Range Networks OpenBTS Development Kit (part number 2115-001) equipment. This manual does not cover full unit configuration or any significant aspects of GSM/VoIP operation. For those topics, see the OpenBTS software manual. This document is intended for use by researchers, developers, and laboratory specialists. It assumes a general familiarity with the Linux operating system and IP networking. 1.2 Disclaimers 1.2.1 Errors and Future Changes Although the information in this manual has been carefully checked for accuracy, and is believed to be correct and current, no warranty, either express or implied, is made as to either its applicability to, or its compatibility with, specific requirements; nor does Range Networks, Inc. assume any responsibility for correctness of this information, or for damages consequent to its use. All design characteristics, specifications, tolerances, and the like are subject to change without notice. 1.2.2 Radio Interference Operation of improperly configured cellular equipment can result in interference to existing services, possibly interrupting public networks and public safety systems, even though the output power of the OpenBTS Development Kit is relatively low. Range Networks, Inc. cannot insure that any of the procedures in this manual will not result in radio interference to other services and networks. 1.3 Abbreviations ARFCN absolute radio frequency channel number 6

1.4. REFERENCES 7 dbm decibel milliwatts MS mobile station (cellular phone or handset) RF radio frequency VDC Volts, direct current 1.4 References This document references the following GSM specifications, which can be downloaded for free from http://webapp.etsi.org/key GSM 03.40: Digital cellular telecommunications system (Phase 2+); Technical realization of the Short Message Service (SMS) Point-to-Point (PP) GSM 04.08: Digital cellular telecommunications system (Phase 2+); Mobile radio interface layer 3 specification GSM 05.05: Digital cellular telecommunications system (Phase 2+); Radio transmission and reception GSM 05.08: Digital cellular telecommunications system (Phase 2+); Radio subsystem link control 1.5 Contact Information For additional information or products referenced in this manual, please contact: Range Networks, Inc. 560 Brannan Street San Francisco, California 94107 United States of America telephone +1 415-778-8700 email support@rangenetworks.com

Chapter 2 Specifications The OpenBTS Development Kit consists of: a mini-itx computer with 8GB msata flash drive, and 2GB RAM, a Range Networks RAD1 wideband digital radio, a +12V, 5A power supply with a power cord, two multi-band rubber duck antennas. two pre-programmed SIM cards, two test phones. 2.1 Mechanical Specifications The computer and the radio are packaged in a desktop enclosure. The Range Networks Rack Mounting Brackets (part number 8710-000-0) are available separately and allow you to mount your OpenBTS Development Kit onto your existing rack (1U, 4.45 cm / 1.75 ). 8

2.1. MECHANICAL SPECIFICATIONS 9 Figure 2.1: OpenBTS Development Kit front panel mechanical. Figure 2.2: OpenBTS Development Kit side view mechanical. 2.1.1 Package Dimensions Figures 2.1 and 2.2 show front and side views with all measurements marked in inches and millimeters. The mechanical dimensions are given in Table 2.1. Range Networks units use standard metric-sized Phillips-head (crosspoint) fasteners throughout. Table 2.1: OpenBTS Development Kit mechanical dimensions. Dimension Value Comments width 30.48 cm (12 ) height 4.45 cm (1.75 ) 1U in optional rack mounting brackets depth 25.40 cm (10 ) min. front clearance 5.08 cm (2 ) min. rear clearance 5.08 cm (2 ) ventilation min. side clearance 3.81 cm (1.5 ) ventilation min. top clearance 0 cm (0 ) touching OK min. bottom clearance 0 cm (0 ) touching OK weight 1.5 kg (3.3 lbs) unit only Starting from the left and moving across, the items on the OpenBTS Development Kit front panel are: Power switch with a LED indicator above it, KEY/SSD USB socket for reset dongle or removable media drive,

10 CHAPTER 2. SPECIFICATIONS ETHERNET Ethernet connector (RJ-45 socket), Rx receive-side RF connector, Tx transmit-side RF connector. 2.1.2 Ventilation Do not block the OpenBTS Development Kit unit on the sides, as they contain the ventilation openings. The unit does not require forced air cooling. 2.2 Environmental Specifications Table 2.2 gives the environmental requirements for the OpenBTS Development Kit. The OpenBTS Development Kit is designed for indoor use, either in a desktop or a rack-mounted installation. However, the unit should not require refrigeration, even in the warm climates. Table 2.2: OpenBTS Development Kit environmental specifications. Parameter operating temperature operating humidity shock and vibration Allowed Range TBD 5% to 95%, non-condensing normal truck transport 2.3 Electrical Specifications The OpenBTS Development Kit takes a 12V, 5A DC power supply. 2.4 RF Specifications The OpenBTS Development Kit is a multi-band unit that can be used in any of the four standard GSM bands: GSM850, EGSM900, DCS1800, PCS1900. It does not include any band-specific filtering in the transmitter or receiver. 2.4.1 RF Output The OpenBTS Development Kit features the Range Networks RAD1 wideband digital radio and has the maximum output power of 100 mw (20 dbm). The actual output level is controlled by the software. On any given ARFCN, the output bandwidth is 270.833 khz. The spectrum mask is verified to comply with GSM 05.05 Appendix A. All noise emissions in the downlink band are at least 50 db below the main signal.

2.4. RF SPECIFICATIONS 11 Table 2.3: RF operating ranges Band Receive Range Transmit Range GSM850 824-849 MHz 869-894 MHz EGSM900 880-915 MHz 925-960 MHz DCS1800 1710-1785 MHz 1805-1880 MHz PCS1900 1850-1910 MHz 1930-1990 MHz 2.4.2 RF Input The OpenBTS Development Kit unit can demodulate GSM signals down to a power level of -110 dbm at the RF connector across its entire receive band. The receiver frequency range is given in Table 2.3.

Chapter 3 BTS Operation In normal operation, there are two interfaces to the OpenBTS Development Kit: the Ethernet interface, for backhaul and administrative access, and the air interface, Um, for subscriber services. 3.1 Installed Components The OpenBTS Development Kit comes with the following components installed and preconfigured: public release of OpenBTS the GSM stack from layer 1 forward error correction up through layer 3; Transceiver the software-defined radio, sipauthserve the SIP registration proxy; SubscriberRegistry the subscriber registry database; smqueue the SMS store and forward server; and Asterisk the SIP softswitch. Note: As of October 2013 OpenBTS version P3.1.3 is installed on all OpenBTS Development Kit systems. 3.2 Source Code The unit also comes equipped with the latest public release source code for the following software components: OpenBTS, smqueue, 12

3.3. INITIAL POWER-UP PROCEDURE 13 sipauthserve, and RRLP aiding server. The source code is located on the file system under /home/openbts/software/. All of the source code directories are installed as SVN working directories, linked to the official public release repository. Any of them can be updated using svn update command on the command line. 3.3 Initial Power-Up Procedure 1. Place the unit on your desk, or install it in a rack nearby. The test phones must be located within 6-20 feet (2-7 meters) of the unit, preferably within the line of sight. 2. Attach the provided antennas to the transceiver (Tx) and receiver (Rx). The receiving antenna must be positioned at an angle of 90 to the transmitting antenna. 3. Power up the unit. It takes up to 3 minutes to load the operating system and all the applications. 3.4 System Access and Control The OpenBTS Development Kit runs Ubuntu Linux operating system. The primary interface to the unit is the UNIX shell, accessed via ssh from the Ethernet connector on the front panel. The unit s Ethernet interface is auto-sensing, requiring no hub or crossover cable. It is shipped with the default IP address of 192.168.0.21. Once the unit is connected to another computer or a network on the 192.168.0.x subnet, it can be accessed via ssh using openbts account name with password openbts. The account is sudo-enabled. The command to issue on any UNIX system, including OS X, is: ssh openbts@192.168.0.21 From a Windows machine, an SSH client, like PuTTY, can be used. Note: Make sure to change the password for user openbts before you connect the OpenBTS Development Kit to the public network. In order to reboot the unit, type the following command at the UNIX command line prompt: sudo reboot Following the reboot, OpenBTS and its related services will start automatically. This process takes about 3 minutes. 3.5 Accessing the OpenBTS Console OpenBTS command line interface (CLI) is used to access (or attach to ) the running OpenBTS software. Log in to the unit via SSH as user openbts and type the following at the command line:

14 CHAPTER 3. BTS OPERATION cd ~;./CLI To exit the command line interface, type quit and hit Return. Doing so does not stop the OpenBTS software. Refer to the OpenBTS software manual for instructions on how to access and modify the OpenBTS settings and runtime information. 3.6 Safe GSM Configuration The OpenBTS Development Kit is preset with the initial safe configuration. Before engaging up the unit, be sure that the OpenBTS configuration is compatible with the surrounding GSM networks so as to prevent disruption of service for existing cells. At a minimum, confirm appropriate values for the following parameters: GSM.Identity.MCC mobile country code. Set to 001. GSM.Identity.MNC mobile network code. Set to 01. The MCC/MNC tuple uniquely identifies a mobile phone operator/carrier. 001/01 is traditionally used for test networks. GSM.Identity.BCC base station color code. Should not match the BCC of any nearby cell. GSM.Radio.Band operating band. Should be 850, 900, 1800 or 1900. GSM.Radio.C0 radio channel number. Should be appropriate for the operating band in use, and not conflict with any cell in the surrounding area. GSM.Radio.ARFCNs number of ARFCNs to use. Set to 1. Control.LUR.OpenRegistration Be sure this is NULL. Control.LUR.UnprovisionedRejectCause cause code to report for failed location updates. Should be set to 0x04 IMSI not in VLR. GSM.RACH.AC access classes. Should be set to 0x0400 to indicate no support for emergency calls. GSM.Radio.PowerManager.MinAttenDB minimum output attenuation. This parameter limits the maximum output power of the unit. The value is an attenuation, so the bigger it is, the less the maximum output power. For initial testing, use a value of 20. Because the OpenBTS Development Kit has no uplink/downlink isolation, increasing the power output will usually result in poor performance and reduced coverage. This is not necessarily a configuration that you will use in your lab, but this set of parameters will minimize the likelihood of interference with existing services while the unit is tested and configured. See the corresponding software manual for further information. 3.7 Initial Testing The default OpenBTS Development Kit configuration provides several tests that can be run independently of the network, with no backhaul:

3.7. INITIAL TESTING 15 1. location updating test, 2. mobile-originated loopback test, 3. mobile-originated call, 4. mobile-terminated delivery of SMS, with and without a parallel call, and 5. autoprovisioning of an handset via SMS. See the Quick Start Guide, and the Test Procedures chapter in the corresponding software manual for detailed description of these test procedures.

Document History Date Doc. Rev. Changes 14 August 2013 0 working draft 4 October 2013 1 First revision 28 October 2013 2 Initial release revision 16