Some Advances in The Indonesian Amateur Radio

Onno W. Purbo, Achmad Daniel Sembiring, Ucu, Yadi Heryadi
Adnan Basalamah, Ismail Fahmi, Basuki Suhardiman.
Amateur Radio Club (ARC)
Institute of Technology Bandung, Bandung 40132
FAX 022 251-2982
E-mail arc-l@itb.ac.id, cnrg@itb.ac.id
http://www.itb.ac.id/

Abstract:
In this paper, we would like to report several advance reseach in the Indonesian Amateur Radio which currently being performed at the Amateur Radio Club at Institute of Technology Bandung (ITB). Some of the advance research including:
•	Amateur Packet Radio Reporting System (APRS).
•	GMSK 64Kbps packet radio systems.
•	Use of WaveLAN 2Mbps CDMA for Metropolitan Area Networking.
•	The first & only Indonesian Internet Gateway for Amateur Packet Radio Network (AMPR-Net).
•	Preparation of Low Earth Orbit (LEO) satellite ground station.

Introduction:
Institute of Technology Bandung (ITB) (http://www.itb.ac.id/) has been one of the leading engineering institution in Indonesia & currently serving as the major Internet gateway for Indonesian educational institution as part of Asia Internet Interconnection Initiatives (AI3) (http://www.wide.ad.jp). ITB is currently using Ku-Band (12-14 Ghz) via JCSat-3 (128E) to connect its gateway to WIDE Project in Japan. It is for the first time in Indonesia we operate satellite link in Ku-Band. Most of its operation is served by the Amateur Radio Club (ARC) member at ITB which contributes to the Computer Network Research Group (CNRG).
Being in a harsh engineering environment, most of the Amateur Radio at ITB has been pushed to its best capacity to do research in various telecommunication areas. In this paper, we would like to expose some of our activities which might be related to the technology used in “conventional” Amateur Radio operations.
Research Activities:
Research activities include:
•	Amateur Packet Radio Reporting System (APRS).
•	GMSK 64Kbps packet radio systems.
•	Use of WaveLAN 2Mbps CDMA for Metropolitan Area Networking.
•	The first & only Indonesian Internet Gateway for Amateur Packet Radio Network (AMPR-Net).
•	Preparation of Low Earth Orbit (LEO) satellite ground station.

Most of our research acitivities are actually aimed towards a more professional research, such as, development of network management / monitoring system, experiment in Ku-Band, Internet caching, etc. The above research activities might be of interest to most Amateur Radio. Let us briefly described each of our activities:
Amateur Packet Radio Reporting System (APRS).

An Amateur Packet Radio Reporting System is basically a remote sensing / tele-metry system using packet radio (AX.25). A typical remote module, which consists of  radio, TNC, microprocessor & GPS / sensors, can be seen in the figure. An additional microprocessor system is build into the system to process the GPS / sensor information to be transmitted to the central / command station.

Shown in the other figure is the map drawn in Windows environment which map the information gathered from the Global Positioning System (GPS) into the map at the command station console / at mobile unit console if we wish.
Via the added microprocessor to the TNC, we can transfer telemetry data from remote. Thus, both position and telemetry information can be displayed on the command console.
APRS is originally developed by the amateur radio in the US. We (at ITB) have managed to engineer most of the equipment including the software at the command station. 
GMSK 64Kbps packet radio systems.
To support our aim to develop low cost computer networking infrastructure, especially in rural area, we are currently developing a very low cost medium speed networking  packet radio system. This system is basically the same as G3RUH 9.6 Kbps packet radio. However,  instead  of creating modulator & demodulator from scratch, we use a single chip modem from MX-COM (http://www.mxcom.com) and put our effort in developing a simple & low cost , wideband FM radio. This project is spearheaded by Adnan Basalamah (adnan@itb.ac.id)
This Wideband FM radio consist of Four part:  Reactance modulator FM Transmitter, Single chip Power Amplifier, a Quadrature FM Demodulator & Signal Source to drive the first downconverter/mixer of this Demodulator.

Not like other Radio Modem which use TNC or Serial  Communication Controller card for interfacing with PC, our modem used LPT port for Interfacing. The Device Driver for this modem is a modified Baycom Device driver, which can be found at many Linux operating system Kernel.
Use of WaveLAN 2Mbps CDMA for Metropolitan Area Networking.
As part of our effort to do high speed networking at low cost, we purchase some of the WaveLAN produced by Lucent Technologies (check out - Lucent Technologies, “WaveLAN ISA Card User’s Guide” Lucent Technologies Bell Labs innovations). It is basically a Code Division Multiple Access (CDMA) board running at 2Mbps in 915 MHz ISM-band.
The ISA Card is put into a 486 motherboard, an additional ethernet card is used on the board to set the board as a router in the network. A homebrew loop yagi antenna at 915 Mhz is connected directly to the output of the WaveLAN card. We managed to link sites at approx. 15 km appart using the plain WaveLAN card at 250 mW @ 915 MHz.
A Metropolitan Area Network (MAN) 2Mbps has been established at our city using this technology. Both UNIX (Linux & FreeBSD) as well as KA9Q NOS variant has been used as the software to drive the router. We found UNIX will perform better in most cases, however, it requires more computing resources, e.g., memory & disk, than NOS.
The first & “currently the only” Indonesian Internet Gateway for Amateur Packet Radio Network (AMPR-Net).
Indonesia has been assigned an AMPR-Net IP Class B of 44.132 with Onno W. Purbo YC1DAV (yc1dav@itb.ac.id) as the country coordinator for the 44.132 network. The IP allocation table for 44.132 can be found at http://www.lp.itb.ac.id/~yc1dav/ip/44-132.htm.
Being the major Internet gateway in Indonesia, we are fortunate enough at ITB to be able to access Internet. Thus, we setup an AMPR-Net gateway at itb.yc1dav.ampr.org (44.132.80.1 & 44.132.16.1) with an ethernet connection to ITB-Net. This machine also can be found as linux.itb.ac.id using Internet Address 167.205.22.103. The machine is running Linux Slakware (kernel version 2.0.27) using the AX.25 kernel activated. One serial port is serving VHF 144.28 Mhz AX.25 1200bps. Another serial port is being prepared for HF 7.032mhz LSB 300bps AX.25.
Tunneling of the AMPRNet traffic can be performed via the gateway as we coordinate with all AMPRNet gateway to tunnel 44-Net traffic over Internet. Nowdays only IPIP encapsulation that being enabled. 
Preparation of Low Earth Orbit (LEO) satellite ground station.
One of our dream is participating in building part of LEO satellite. However, to perform such engineering task we need to make sure we have the capacity to operate one. We have installed a LEO ground station which consisted of:
•	DX Computer (funded by ARC-ITB) running WISP software to track the birds.
•	Elevator / Azimuth dual controller, Kenpro G5400B
•	Rotators at the antenna.
•	Antena model AOP no1 by Cushcraft Corp, cross-yagi (donated by YB0EBS)
•	Kansas City Tracker/Tuner (donated by N5SNN / YG1QN)
•	Icom IC 970H (in progress with the help from YB1CS)
•	Kenwood TS 430S HF  transceiver (donated by YC1HCE)
•	Icom IC 726 HF/50Mhz all mode transceiver
•	PacComm TNC 9,6 kbps (donated by YC1DAV)
 
As we are still waiting for the arrival of IC970, we are currently only able to track & monitor the birds. Telemetry of DOVE-17 would be one of our regular exercise.