Journal Predator ... Be Careful with a fooL

A predatory publisher may ...
(1) Publish papers already published in other venues/outlets without providing appropriate credits
 
 (2)  Use language claiming to be a “leading publisher” even though the publisher may only be a startup or a novice organization.
 
  (3) Operate in a Western country chiefly for the purpose of functioning as a vanity press for scholars in a developing country.
 
 (4)  Do minimal or no copyediting.
 
 (5)   Publish papers that are not academic at all, e.g. essays by laypeople or
    obvious pseudo-science.

 (6)   Have a “contact us” page that only includes a web form, and the publisher hides or does not reveal its location

=====================================================================
The following practices are considered to be reflective of poor journal standards and, while they do not equal predatory criteria, potential authors should give due consideration to these items prior to manuscript submissions:

  (1)   The publisher copies “authors guidelines” verbatim (or with minor editing) from other publishers.
   (2)  The publisher lists insufficient contact information, including contact information that does not clearly state the headquarters location or misrepresents the headquarters location (e.g., through the use of addresses that are actually mail drops).
(3)    The publisher publishes journals that are excessively broad (e.g., Journal of Education) in order to attract more articles and gain more revenue from author fees.
 (4)    The publisher publishes journals that combine two or more fields not normally treated together (e.g., International Journal of Business, Humanities and Technology).
  (5)  The publisher requires transfer of copyright and retains copyright on journal content. Or the publisher requires the copyright transfer upon submission of manuscript.
(6)     The publisher has poorly maintained websites, including dead links, prominent misspellings and grammatical errors on the website.
 (7)    The publisher makes unauthorized use of licensed images on their website, taken from the open web, without permission or licensing from the copyright owners.
 (8)    The publisher engages in excessive use of spam email to solicit manuscripts or editorial board memberships
   (9)  The publishers’ officers use email addresses that end in .gmail.com, yahoo.com some other free email supplier
  (10)   The publisher fails to state licensing policy information on articles or shows lack of understanding of well-known OA journal article licensing standards.
  (11)   The publisher lacks a published article retraction policy or retracts articles without a formal statement; also the publisher does not publish corrections or clarifications and does not have a policy for these issues.
    The publisher does not use ISSN numbers, DOI numbers or uses them improperly.
 (12)   For the name of the publisher, the publisher uses names such as “Network,” “Center,” “Association,” “Institute,” and the like when it is only a publisher and does not meet the definition of the term used.
   (13)  The publisher has excessive advertising on its site to the extent that it interferes with site navigation and content access.
(14) The publisher has no membership in industry associations and/or intentionally fails to follow industry standards.
  (15)  The publisher includes links to legitimate conferences and associations on its main website, as if to borrow from other organizations’ legitimacy, and emblazon the new publisher with the others’ legacy value.
 (16)   The publisher displays prominent statements that promise rapid publication and/or unusually quick peer review.
 (17)   The publisher focuses on authors (not readers) and on getting their fees at the expense of due quality, and offers few or no value adds to readers such as RSS feeds, hotlinked references, or the like.
 (18)   The publisher creates a publishing operation that is set up and run by a single individual who engages in rapacious entrepreneurial behavior. The individual might have business administration experience, and the site may have business journals but it also has journals that are outside the experience of the entrepreneur or anyone on staff.
 (19)   The publisher or its journals are not listed in standard periodical directories or are not widely cataloged in library databases.
(20)    The publisher copies or egregiously mimics journal titles from other publishers.
 (21)   The publisher uses text on the publisher’s main page that describes the open access movement and then foists the publisher as if the publisher is active in fulfilling the movement’s values and goals.
  (22)  None of the members of a particular journal’s editorial board have ever published an article in the journal.

Shale Gas

Keunggulan dan Kelemahan Shale Gas

Shale gas bisa menjadi salah satu sumber energi yang paling penting di tahun-tahun mendatang, dan sebagaiman dengan sumber energi lainnya shale gas memiliki keunggulan dan kelemahan. Sebelum berbicara lebih lanjut tentang keunnggulan dan kelemahan shale gas pertama-tama kita harus mendefinisikan apa itu shale gas. Shale gas adalah gas alam yang diperoleh dari serpihan batuan shale atau tempat terbentuknya gas bumi.

Ketika berbicara mengenai keunggulan shale gas, banyak pakar energi yang akan memberikan fakta bahwa shale gas menghasilkan emisi karbon yang secara signifikan lebih sedikit dibandingkan dengan batubara (shale gas mengeluarkan sekitar setengah dari emisi karbon batubara).

Shale gas juga merupakan sumber energi yang melimpah, misalnya, diperkiraan di Amerika Utara saja terdapat sekitar 1.000 triliun kaki kubik shale gas yang cukup untuk memasok gas alam untuk USA selama 50 tahun atau lebih. Analisa terakhir juga menunjukkan bahwa shale gas bisa menyediakan hingga setengah pasokan gas USA pada tahun 2020.

Shale gas juga dapat menurunkan biaya energi karena produksi shale gas kemungkinan akan menyebabkan penurunan harga gas alam secara signifikan. Produksi shale gas yang besar juga akan membantu meningkatkan keamanan energi, dan membantu mengurangi ketergantungan pada bahan bakar fosil asing yang mahal.

Shale gas juga bisa menjadi pilihan energi yang lebih bersih bagi negara-negara berkembang yang saat ini sangat bergantung pada batubara, sumber energi yang paling kotor.

Ada juga beberapa kerugian dari shale gas yang akan di sebutkan di sini. Shale gas meskipun (secara signifikan) merupakan sumber energi yang lebih bersih dibandingkan dengan batubara, masih menghasilkan emisi karbon yang signifikan, sehingga menjadi kurang dapat diterima dari sudut pandang lingkungan dibandingkan sumber energi terbarukan lainnya. Ada juga bahaya lingkungan dalam bentuk  potensi kebocoran gas metana dari sumur shale gas yang bisa menurunkan efek pengurangan karbon dioksida dan manfaat iklim dengan beralih dari batubara ke shale gas.

Perkembangan industri shale gas yang cepat bisa memperlambat perkembangan lebih lanjut dari industri energi terbarukan, terutama jika shale gas (bila sesuai yang diperkirakan) menjadi salah satu pilihan energi yang paling murah. Energi terbarukan telah lama sulit bersaing dengan batubara, dan dengan tersedianya shale gas yang murah, ini bisa memperburuk perkembangan di sektor energi terbarukan.

Saat ini, biaya ekstraksi shale gas lebih tinggi dibandingkan dengan biaya untuk ekstraksi gas konvensional atau batubara, tetapi kemajuan lebih lanjut teknologi pengeboran dapat membantu mengurangi biaya ekstraksi shale gas.

Masih terlalu dini untuk mengatakan bahwa shale gas akan menjadi salah satu faktor penentu di pasar energi global, tetapi potensinya tidak bisa diragukan lagi.

Tugas Mikroprosesor - Kelompok Selasa

Materi dapat di download di http://users.abo.fi/mats/codeopt2013/slides/IntelCore_i7.pdf
 Ketentuan
1. Kertas Ukuran Kwarto
2. 5 Halaman

- Pendahuluan
- Isi/ Bahasan
- Kesimpulan
-referensi

Dikumpulkan Selasa, 28 Oktober 2014

Cisco Fundamental 1 - UAS

IP Address Classes

SIP-SIL

==================
Arskom
==================


Pertemuan 1
===========
1.    Perbedaan arsitektur dan organisasi komputer
2.    Struktur dan fungsi sistem komputer

Pertemuan 2
===========
Evolusi arsitektur komputer

Pertemuan 3
===========
1.    CPU
2.    Konsep register
3.    Unit memori

Pertemuan 4
===========
1.    Sistem bus komputer
2.    Struktur dan interkoneksi bus
3.    Sistem bus masa depan / PCI bus

Pertemuan 5
===========
1.    Memori semikonduktor
2.    Internal memori
3.    DRAM

Pertemuan 6
===========
1.    Eksternal memori
2.    Piringan magnetik

Pertemuan 7
===========
1.    RAID
2.    Memori optis
3.    Pita magnetik

Pertemuan 8
===========
...........UTS........

Pertemuan 9
===========
1.    Konsep I/O
2.    Modul I/O
3.    I/O terprogram
4.    Interupsi penggerak I/O

Pertemuan 10
===========
1.    DMA
2.    I/O processor
3.    Antarnuka eksternal

Pertemuan 11
===========
1.    Konsep OS
2.    Teknik penjadwalan

Pertemuan 12
===========
Tipe tipe memori manajemen dan aplikasinya

Pertemuan 13
===========
1.    Komunikasi data
2.    Interkoneksi antar Komputer didalam sistem komunikasi data

Pertemuan 14
===========
1.    Teknologi saluran komunikasi
2.    Media transmisi
3.    Processor komunikasi
4.    Protokol dan format transmisi

Pertemuan 15
===========
1.    Konsep multi Processing
2.    Sistem terdistribusi

Pertemuan 16
===========
1.    Multiprocessing
2.    Pemprosesan paralel

 =========================== selesai =============================

=============
Orkom
=============


Pertemuan 1
===========
1.Perbedaan arsitektur dan organisasi
2.Konsep dari organisasi
3.Struktur dan fungsi

Pertemuan 2
===========
1.Memori semi konduktor
2. Organisasi memori

Pertemuan 3
===========
1.Memori semi konduktor
2. Organisasi memori

Pertemuan 4
===========
1.Cache memory
2.Direct Mapping cache

Pertemuan 5
===========
Assosiative mapping cache

Pertemuan 6
===========
Set Assosiative Mapping cache

Pertemuan 7
===========
Algorima untuk Cache

Pertemuan 8
===========
.............UTS.........

Pertemuan 9
===========
1.Pengertian dasar pipe line
2.Pipelining Analogy

Pertemuan 10
===========
1. Pipeline stage
2. Pipeline instruction exceution

Pertemuan 11
===========
1.Structural hazard
2.Branch

Pertemuan 12
===========
1.Konsep dasar multiprocessor/ parallelprocessor
2.Taxonomy multiprocessor/ parallelprocessor

Pertemuan 13
===========
1.SISD
2.SIMD
3.MISD
4.MIMD

Pertemuan 14
===========
1.Time shared or common bus
2.Miltiport memory
3.Central control unit

Pertemuan 15
===========
1.Operating system issues
2.Studi kasus

Pertemuan 16
===========
Review

================================selesai ===========================

=============
Mikroprosesor
=============

Pertemuan 1
===========
1.Mikroprosesor generic
2.Intro Struktur internal
3.Intro Sistem bus

Pertemuan 2
===========
1.Sinyal kontrol
2.Pewaktuan

Pertemuan 3
===========
1.Konsep register
2.General purpose register
3.Special purpose register

Pertemuan 4
===========
1.Format instruksi
2.Format data

Pertemuan 5
===========
1.Set instruksi
2.Penggolongan set instruksi

Pertemuan 6
===========
1.Data transfer
2.Operasi aritmatika dan logika
3.Operasi pencabangan
4.Subroutine

Pertemuan 7
===========
1.Bus alamat
2.Bus data
3.Bus control
4.Internal bus

Pertemuan 8
===========
..............UTS.........

Pertemuan 9
===========
1.Mode pengalamatan Implied
2.Mode pengalamatan immediate
3.Mode pengalamatan direct
4.Mode pengalamatan indirect dan seterusnya

Pertemuan 10
===========
1.MI
2.NMI
3.Reset
4.Fungsi interupsi
5.Respon interupsi

Pertemuan 11
===========
1. Jenis-jenis memori
2. Memori semikonductor

Pertemuan 12
===========
Peta memori

Pertemuan 13
===========
Antar muka memori

Pertemuan 14
===========
1.I/O serial danI/O paralel
2.Peta I/O
3.Pemetaan I/O di memori

Pertemuan 15
===========
Antar muka I/O

Pertemuan 16
===========
review

===================================selesai=============================


=================================================
Pemrosesan Paralel
=================================================
Pert 01
1.    Evolusi sistem komputer
2.    paralelisme dalam sistem uniprosesor
3.    Struktur komputer paralel

Pert 02
1.    Klasifikasi arsitektural
2.    Aplikasi pemprosesan paralel

Pert 03
1.    Struktur memori
2.    Virtual memori

Pert 04
1.    Alokasi dan manajemen memori
2.    Cache memori

Per 05
Subsystem I/O

Pert 06
Pipelining

Pert 07
Instruksi Pipelining
Aritmatika Pipelining

Pert 08
1.Pipelined Processor
2.Vector Processing

Pert 09
=====UTS====

Pert 10
SIMD Array Processor
SIMD Interkoneksi Jaringan

Pert 11
Algoritma Parallel Array Processor
Associative Array processor

Pert 12
1.Struktur Fungsional
2.Interkoneksi Jaringan

Pert 13
Organisasi Paralel Memory
Sistem Operasi Multiprosesor

Pert 14
Mekanisme Komunikasi Interprocess
Sistem Deadlock dan Protection

Pert 15
1.Strategi Penjadwalan Multiprocessor
2.Algoritma Paralel

Materi Cisco 1 - Sept.2014

Klik disini untuk download

Materi Arsitektur Komputer - Sept.2014

Download here

Kalender Akademik 2014-2015 Univ. Budi Luhur

Kalender Akademik 2014-2015

Onno W Purbo - Research 1993 Universitas Waterloo USA

From: owpurbo@nyquist.uwaterloo.ca
To: amcgee@netcom.com
Date: Tue, 20 Jul 93 14:14:23 -0400


                      AN ALTERNATIVE APPROACH TO BUILD LOW COST
                     TCP/IP-BASED WIDE AREA NETWORK IN INDONESIA

                                    Onno W. Purbo
                              owpurbo@sunee.waterloo.edu
                              yc1dav@ve3.yc1dav.ampr.org
                  Department of Electrical and Computer Engineering
                                University of Waterloo
                          Waterloo, Ontario, CANADA N2L 3G1
                     ph: [519] 885-1211x2872 FAX: [519] 746-3077

                                    on leave from:
                         Department of Electrical Engineering
                     Inter University Center on Microelectronics
                           Institute of Technology Bandung
                                    Bandung 40132
                                      INDONESIA

                                       ABSTRACT

                    Based  on a  case study  in the  amateur radio  in
               Indonesia, an attempt to build a TCP/IP-based wide area
               computer network is described. The network architecture
               and  its protocols as well as the low-cost hardware and
               software designs are  briefly reviewed. Experiments  to
               link  the  network into  the international  network are
               reported. Unlike most Government's or  private sector's
               that   adopts   capital   intensive   high   technology
               information systems,  ours rely  heavily on  the active
               participation  of the  members. The  use of  a low-cost
               PC-based  equipments  is  proven  to  be  significantly
               reduced the overhead costs.

          INTRODUCTION

               The  establishment  of  an  infra-structure  of  information
          systems plays an important  role to encourage the socio-economics
          and science-technology developments both at regional and national
          levels.  In view  of  the significant  technological advances  in
          microelectronics,  high  performance computing  equipments become
          more affordable and  widely use in most modern offices as well as
          in  daily household activities.  Data communication networks have
          become  increasingly  important  to   accommodate  the  need  for
          exchanging information among various  Local Area Network (LAN) in
          various organizations / institutions to participate in the socio-
          economics  as  well  as  science-technology  development  of  the
          region.
               In the case of Indonesia,  to maintain an interconnection of
          a  small  LAN (10-20  microcomputers)  over  our commercial  X.25
          packet switching network (SKDP) can easily take US$100-$200/month
          not  to mention the more advanced commercial data network such as
          ISDN. Since net income of most civil servants is within the range
          of  US$50 to $100/month, to  maintain such a  LAN connection over
          SKDP to  form a Wide  Area Network  (WAN) is considered  to be  a





          luxury.   These   situations  have   unfortunately   impeded  the
          development  of  computer  network  in  Indonesia,  such  as  the
          Indonesian Universities Network (UNINET)  initiated by the Center
          for  Computer  Science   at  University  of   Indonesia,  Jakarta
          (PUSILKOM-UI).
               In this paper, an alternative approach to develop a low cost
          WAN,  a  case  study in  the  amateur  radio  in Indonesia,  with
          emphasis  on  the   efforts  to  build  prototypes   as  well  as
          experiments  in packet  radio network  will be  presented. Unlike
          most government's  and other  private sectors' approach  to adopt
          highly centralized and capital  intensive technology to build the
          information  system  infra-structure,  the  amateur  packet radio
          network  uses low-cost  hardware and  software equipments  and is
          decentralized in nature which relies heavily on the participation
          of the members. In other words,  each member may participate as a
          router within the  network to maintain  the network integrity  as
          well as to push  the overall overhead costs towards  minimum. The
          modem  and  radio transceiver  may be  obtained  in the  range of
          US$200 to $500 with considerably lower operating costs than  that
          commercial  X.25   PSN.  Considering   the  advantages  of   such
          technology   in   terms   of    overhead   costs   as   well   as
          decentralization, it would be  interesting to adopt such approach
          to  develop our very own  low cost TCP/IP-based  WAN in Indonesia
          for private as  well as  informal sectors to  elevate our  socio-
          economics  as  well as  science-technology  capacity  based on  a
          cooperation among the members of the network.
               This paper is organized as  follows. In the second  section,
          the  network architecture with  emphasis in  TCP/IP-based network
          will  be  briefly  reviewed.  The  packet  radio  network  as  an
          alternative physical  layer will  be presented in  section three.
          Attempts  to build  hardware and  software prototypes  for packet
          radio  network  at the  Institute  of  Technology Bandung  (ITB),
          Indonesia will be reported in section four. In section five, some
          results  of  our experiments  in  AX.25 and  TCP/IP  over amateur
          packet radio network will be presented. Section six is a summary.


          BRIEF REVIEW ON COMPUTER NETWORK ARCHITECTURE

               Traditionally, the architecture of a computer network may be
          represented by  the  famous  7  OSI protocol  layers  [1].  These
          layers,  in terms  of its  functionality from  the lowest  to the
          highest  level, are  physical layer,  link layer,  network layer,
          transport   layer,   session   layer,  presentation   layer   and
          application  layer. An end user  does not have  to understand how
          these  layers  interacts to  use  the  computer network.  Various
          application  programs  on the  application layer  of TCP/IP-based
          network have been  developed such as electronic  mail (SMTP) [2],
          remote  login  (TELNET) [3],  file  transfer (FTP)  [4]  and news
          transfer  (NNTP) [5].  Recently, more  advanced protocols  on the
          application  layer  have  been  developed  to  maintain   network
          integrity  as  well as  to  monitor network  performance  such as
          Simple   Network  Management  Protocol  (SNMP)  [6]  and  Routing
          Information Protocol (RIP) [7].





               A  simpler  network  architecture  is  used  in  the  actual
          implementation of TCP/IP-based computer network. Fig.1 shows  the
          major difference between TCP/IP  architecture with respect to OSI
          architecture in which the former has  no session and presentation
          layers. The computer's operating system such as UNIX used in most
          TCP/IP  platform will essentially perform the task of session and
          presentation layer.  The  tasks  of the  other  layer  in  TCP/IP
          architecture are essentially the  same as the corresponding layer
          in OSI stack protocols.
               An  example of  various protocols  in network  and transport
          layer in  TCP/IP  family  is  shown in  Fig.  2.  Each  of  these
          protocols has its own task to run the network properly. The major
          protocols used in normal network operations are InterNet Protocol
          (IP)  [8] in the network layer  and Transmission Control Protocol
          (TCP)  [9] in the  transport layer. TCP  is a connection-oriented
          protocol that provide  a reliable, full-duplex, byte stream for a
          user  process in  layer  5 and  above.  IP is  a  connectionless-
          oriented protocol  that provides the packet  delivery service for
          the  transport  layer.  IP  uses  Internet  address  known  as IP
          address. Address Resolution Protocol  (ARP) [10] maps an Internet
          address into  hardware address used  by the link  layer protocol.
          Reverse Address  Resolution Protocol (RARP) [11]  maps a hardware
          address  into an  Internet  address. Note  that  not all  network
          applications  require the use  of ARP and  RARP. InterNet Control
          Message  Protocol   (ICMP)  [12]   handles   error  and   control
          information between gateways  and hosts.  User Datagram  Protocol
          (UDP)  [13], a connectionless  protocol, is  for user  process in
          layer 5 and  above. However,  unlike TCP, there  is no  guarantee
          that UDP datagrams ever reach their intended destination.
               The physical  and link  layer protocols  used in  a computer
          network may  vary depending on the  form of the network.  In most
          high-speed LANs,  10Mbps Ethernet  or Token Ring  physical layer,
          the IEEE 802 link layer protocol [14] is normally used. To form a
          Wide Area  Network, commercial  packet switching network  or even
          ISDN may be used with  various link layer protocol such  as CCITT
          X.25 [15]. The interconnection of various physical and link layer
          protocols  in various  LAN / WAN  to form  a nation  wide or even
          worldwide computer network is  transparent to the users by  using
          InterNet Protocol (IP) in  TCP/IP-based WAN. The TCP/IP-based WAN
          has currently  emerged into  worldwide computer network  known as
          InterNet which, to the best of our knowledge,  includes Singapore
          and Australia in the South East Asia region.


          AMATEUR PACKET NETWORK AS AN ALTERNATIVE APPROACH

               As mentioned  in the  previous section,  the  use of  TCP/IP
          protocols allows us to interconnect various computer network with
          different data communication medium  to form a WAN  while keeping
          the whole process transparent to the end users. Given the fact of
          high overhead costs to use the current commercial data network in
          Indonesia, packet radio network technology seems to give an ample
          hope  to build  a  low  cost WAN  in  Indonesia  while keeping  a
          reasonable  performance.  In this  section, typical  packet radio





          equipments will be described.
               As  shown in Fig. 3, a typical packet radio station consists
          of a microcomputer (most likely a PC clone) attached to a VHF/UHF
          radio transceiver via a  Terminal Node Controller (TNC).  In more
          advanced  packet radio  station especially  for gateway  or high-
          speed trunk nodes, the layout of the station may be  different to
          accommodate the need of high speed operations. The physical layer
          of the system  consists of  the radio transceiver  and the  modem
          within the TNC.
               A TNC  is typically a dedicated 8  bit microprocessor system
          with  its own  peripherals to  perform AX.25 link  layer protocol
          tasks. It is connected to the microcomputer via a serial port and
          to the  radio transceiver via a modem, mostly Bell 202 AFSK modem
          [16]  (high  speed  operations  may  have   different  modulation
          scheme).  The  AX.25 (Amateur  X.25)  protocol  [17] is  slightly
          different than that  of the  CCITT X.25 used  in most  commercial
          packet switching networks. The  AX.25 protocol uses amateur radio
          callsign in the address field and sub-station ID to allow several
          stations  using  the  same   callsign.  Furthermore,  it  has  UI
          (Unnumbered Information) frame for  broadcast messages as well as
          to  carry messages using high level protocols, such as TCP/IP, in
          more efficient manner.
               The data  transaction procedures used by  the AX.25 protocol
          is similar to  CCITT X.25  protocol [17]. The  information to  be
          sent is sliced into packets and sent over the radio and, finally,
          assembled  into the  original information  at the  receiver node.
          Poll-Final  bit as well as other link control procedures, such as
          Unnumbered Acknowledged (UA), Receiver Not Ready  (RNR), Receiver
          Ready (RR),  Disconnect (DISC), Disconnected Mode  (DM) etc., are
          used  to control  the  data flow  [15][17].  Note that  the  data
          transaction  procedures may be ignored when UI frame is used with
          TCP/IP data on top.
               Using  the ID bits in the  header of AX.25 protocol, one can
          identity the type of  information carried by the AX.25  frame. In
          this fashion,  the TCP/IP protocol is carried on top of the AX.25
          protocols.  The microcomputer  attached  to the  TNC decodes  the
          TCP/IP protocols as well  as performs the network tasks.  The LAN
          interconnection over  the radio can  be easily done  by attaching
          both LAN card, such as  Ethernet or Token Ring, and the  TNC with
          radio transceiver on  the same microcomputer.  Routing of the  IP
          frame is performed  by the software running on PC to decide which
          port to be sent.


          ATTEMPTS TO BUILD HARDWARE AND SOFTWARE PROTOTYPES

               In  this section, we report our attempts at the Institute of
          Technology Bandung  (ITB) in  Indonesia to  develop and  to adopt
          various hardware and software prototypes for  use in packet radio
          network.  Several  research  groups  have been  involved  in  the
          development of the necessary  equipments for packet radio network
          which include  the group  of Prof.  Dr. Iskandar Alisyahbana  (EE
          Dept ITB)  especially on  high speed  packet radio  prototypes as
          well  as  joint  research  with  VITA  (Volunteers  In  Technical





          Assistance) a Washington D.C.  based NGO to use the  Packet Radio
          Satellite  (PACSAT); the group of  Dr. S. Nasserie  and Dr. Adang
          Suwandi (EE Dept ITB) especially to develop high-performance low-
          speed  packet  radio   prototypes  as  well   as  to  study   the
          possibilities in  adopting such approach on  the Indonesia's geo-
          stationary satellite PALAPA; the  group of Dr. Kusmayanto Kadiman
          (PIKSI-ITB) is  working  especially in  TCP/IP-based Campus  Wide
          Network with  possible interconnection over the  radio; the group
          at IUC Microelectronics ITB  especially in TCP/IP-based IC design
          center  and  the  ITB-Amateur  Radio  Club  (ARC)  especially  on
          hardware  prototypes for low end users. In terms of the hardware,
          the prototypes may be classified into:

             1.     Prototypes of 1200 bps AFSK modems.
             2.     Prototypes of PC add-on TNC with AFSK modems.
             3.     Prototypes of 56Kbps high-speed packet radio systems.

          In  terms of software, we  are currently using  and enhancing the
          existing public domain packet radio software which may be  freely
          used in amateur radio and educational institutions.
               To provide an end user  with a reasonable hardware necessary
          to  become a part of the packet  radio network, a simple 1200 bps
          AFSK modem is developed. This modem relies on the assumption that
          PC  MS-DOS machines  can be  easily obtained  and, thus,  all the
          necessary AX.25  protocols are  written in  the form of  software
          running on  the PC to  utilize the computing  power of the  PC as
          well  as  to reduce  the hardware  costs.  Typical layout  of the
          hardware prototype  is shown in Fig. 4.  The internal PC timer is
          utilized as a reference  to form and to decode  the packet signal
          over the serial  or the parallel port. The digital signal is then
          converted into audio  signal by  an AFSK modem  connected to  the
          serial or  parallel ports which then  can be fed into  VHF or UHF
          transceivers. Three different AFSK  modem designs are possible to
          use which include single  chip modem TI TCM3105 [18]  (adopted by
          the ITB-Amateur  Radio Club), single  chip modem AMD  Am7910 [16]
          and  a  combination  of  XR2207-XR2211 [19]  (adopted  by  Dr. S.
          Nasserie's group). Typical  cost to  built such modem  is in  the
          range  of   US$20-$40.  This   approach  has   been  successfully
          implemented and tested by our colleague Suryono Adisoemarta N5SNN
          to perform low cost  (less than US$40) TCP/IP operation  from his
          microcomputer over radio. The major problem in this approach, the
          PC's  computing  power is  tied up  to  perform AX.25  link layer
          protocol tasks and, thus, difficult to perform high speed (faster
          than 2400 bps) TCP/IP operations.
               For  advanced  packet  radio  applications  such  as  TCP/IP
          operations,  the PC  computing power should  be freed  to perform
          high-level networking  tasks. This can  be done by  leaving lower
          level protocol operations to a dedicated hardware. Prof. Iskandar
          Alisyahbana and Dr. S.Nasserie  group are adopting the High-Level
          Data link  Controller chip (HDLC)  Intel 8273 to  help performing
          AX.25  link layer protocol function. Typical layout of the system
          is shown in  Fig. 5, the  Intel 8273 is  imbedded into an  add-on
          card on  PC with an  AFSK modem attached  to it. Since  the AX.25
          protocol uses  similar transaction  procedures as the  HDLC chip,





          this  is simplify the making  of hardware and  software for AX.25
          operation. Furthermore, TCP/IP operation becomes easier with more
          computing  power  on  the  PC  may  be  dedicated  to  high-level
          networking tasks.
               As the  network grows  to interlink various  high-speed LANs
          into  WAN, it is  most likely the  long-distance packet switching
          backbone  nodes will  experiencing  a heavy  traffic which  might
          create network congestion. To accommodate the need for inter-city
          high-speed packet radio trunk, Prof. Iskandar Alisyahbana's group
          is currently working on 56Kbps high-speed packet radio system  on
          900MHz and 1.2GHz. In Fig. 6  is shown the typical diagram of the
          system.  It utilized special I/O  card on PC  to allow high-speed
          data  transfer  from the  modem directly  to the  PC-memory (RAM)
          through DMA operations. An  56Kbps MSK RF modem operate  at 29MHz
          is adopted. A transverter from 29MHz  to 900MHz or 1.2GHz is used
          to translate the frequency into the actual operating frequency.


          EXPERIMENTS ON AX.25 AND TCP/IP-BASED PACKET RADIO NETWORK

               In this section, we report on our experiment on packet radio
          network, an experiment  which has  been performed  by the  author
          using his  amateur radio  station, licensed in  Waterloo, Canada.
          The equipment consists of a microcomputer connected to a Terminal
          Node  Controller in KISS (Keep  It Simple Stupid)  mode for AX.25
          and TCP/IP operations on 144MHz VHF band.
               In the  amateur radio,  the major Metropolitan  Area Network
          (MAN) frequencies are normally located in simplex band in  144MHz
          and 435MHz  running at  1200-2400bps. Intercity  high-speed trunk
          are normally running  at 4800-9600bps and in some areas in the US
          and Canada are running at 56Kbps  or higher. For intercontinental
          back bone, a slow  300-1200bps HF packet radio links  are usually
          used.  However,  more  recently,  as  the  Amateur  Packet  Radio
          Satellites (PACSAT) becomes available some long distance traffics
          are carried on-board the satellites.
               In  the  case  of  the  amateur  packet   radio  network  in
          Indonesia,  most MAN are concentrated  in 435MHz UHF  band and in
          some areas in 144MHz VHF band. Most areas are served by a network
          of Packet  Radio Bulletin Board Systems (PBBS).  7 MHz and 14 MHz
          band  are  normally used  as the  national and  the international
          backbone, respectively. Recently, a PACSAT gateway in Jakarta has
          been established to perform long distance message forwarding over
          the PACSAT. Unlike  in most western nations, TCP/IP operations in
          Indonesia  are still very sporadic  in terms of  the stations and
          operation time. Work is currently underway at ITB-ARC to link the
          TCP/IP operation  on the radio to  the existing LAN.  We hope the
          establishment  of LAN  connection over  the radio will  give more
          incentives to operate such high performance TCP/IP protocols over
          the radio.
               Experiments to  deliver messages  between North  America and
          Indonesia via amateur packet radio network have been performed by
          the  author in  cooperation with  several amateurs  in Indonesia,
          especially Robby  Soebiakto YB1BG  in Jakarta. In  Indonesia, the
          method to exchange long distance messages is  still restricted to





          PBBS only messages.  Along the  way to reach  Indonesia, we  have
          exercised various  methods to deliver the messages from Canada to
          Indonesia  which include  direct  delivery to  the nearest  PBBS;
          piggy-backing over the InterNet and use TCP/IP network in amateur
          radio  to reach  the PBBSes  in Australia  and Hawaii  from which
          messages   are  then   carried   over  HF   link  to   Indonesia.
          Store-and-forward  method is  used  to deliver  messages in  PBBS
          network.  In other  words, messages  are stored  in a  PBBS prior
          forward it  to the next  PBBS and  the process continue  until it
          reaches  the destination.  The PBBS program  can perform  as both
          User  Agent (UA) and Mail Transfer  Agent (MTA) at the same time.
          The  author is  currently in  a regular  e-mail contact  via PBBS
          network  with  Indonesia.  The   typical  turn  around  time  for
          exchanging  messages between  Indonesia and  Canada is  about 2-4
          days depending on the path and the condition of the network.
               Other  method  to send  long  distance messages  is  via the
          Amateur  Packet  Radio  Satellite   (PACSAT).  PACSATs  are  tiny
          satellites  with polar orbit  hovering at  about 900km  above the
          earth.  It is built and operated by the Amateur Satellite (AMSAT)
          [20].  The on-board  microcomputer has  about 4  MB RAM  disk for
          store-and-forward  services. A PACSAT  ground station  may access
          PACSAT  about four  or  five times  a day  with about  14 minutes
          access  window. At 9600bps with  only 56 minutes  access time per
          day  can move  nearly  5.7 million  bytes  of data  [21].  PACSAT
          broadcast protocol on top  the AX.25 link layer protocol  is used
          which  enables PACSAT  users to  catch files  being requested  by
          other  users so as  to increase the  satellite's efficiency [21].
          Figure  7. shows the path used by  the author to send messages to
          Indonesia via PACSAT. WA0PTV  in Western New York area  and YB0QC
          in Jakarta act  as PACSAT  gateway nodes. To  send the  messages,
          YC1DAV (author's machine) connects and delivers messages directly
          to WA0PTV via  the existing AX.25  as well  as using the  network
          layer  protocol.  Subsequently, messages  will  be  uploaded into
          satellite by WA0PTV  and in less than 12  hours will be retrieved
          by  YB0QC in  Jakarta.  The major  problem  faced by  the  PACSAT
          gateways is no standard to perform third party message deliveries
          and,  thus,  some  processes have  to  be  manually  done by  the
          operators.
               Especially  in North  America, Europe, Australia  and Japan,
          the TCP/IP-based network  in amateur  radio is  quite active  and
          known  as   AMPRNet  under  the  ampr.org   domain  in  InterNet.
          Experiments have  been performed to operate  a world-wide AMPRNet
          TCP/IP  network with  Internet access  via a  AMPRNet  - InterNet
          gateway  installed by  the University  of Waterloo  Amateur Radio
          Club VE3UOW. Similar approach has been installed  and operated by
          various university-based Amateur Radio Club as shown in Table 1.
               The network topology is  shown in Fig. 8. at.ve3uow.ampr.org
          (also  known as at.ve3uow.watstar.waterloo.edu  in Internet) acts
          as  the packet  radio -  Internet gateway.  at.ve3uow.ampr.org is
          attached  to a 10Mbps Token  Ring LAN at  University of Waterloo,
          from which one may reach wider networks, such as Internet, and to
          radio via its serial  port connected to the local  amateur packet
          radio  network.  This approach  has been  used  as a  test-bed to
          explore the possibility  in interconnecting a low-speed  network,





          such  as packet radio network, with a high-speed network, such as
          Token Ring  LAN as well  as to enhance  the software used  by the
          gateways and the AMPRNet nodes. The AMPRNet Domain Name Server in
          InterNet has assisted other machines in InterNet to reach AMPRNet
          hosts.  This  has  enabled  us  in  AMPRNet  to communicate  with
          Internet hosts  utilizing our AMPRNet-InterNet gateway  as our MX
          (mail exchanger)  host.  Furthermore, the  existence of  AMPRNet-
          InterNet gateways  allow AMPRNet hosts to  reach distance AMPRNet
          hosts  by piggy-backing its  IP frames  over Internet  and, thus,
          long distance networking tasks may be done. TCP/IP protocols have
          proven  to be  robust  and reliable  in  low-speed and  congested
          packet radio network.

                      Table 1. Lists of AMPRNet-InterNet gateway
                               (as of 16 December 1991)


               gateway                         location
            at.ve3uow.ampr.org              Waterloo, Canada

            ve3ocr.ampr.org                 Ottawa, Canada

            minnie.vk1xwt.ampr.org          Canberra, Australia
            vk3rum.ampr.org                 Melbourne, Australia

            gw.af2j.ampr.org                Pennsylvania, US

            gw.n3eua.ampr.org               Colorado, US
            wa4ong.ampr.org                 Virginia, US

            uhm.ampr.org                    Honolulu, Hawaii, US

            hb9zz.ampr.org                  Switzerland
            hamgate.wb5bbw.ampr.org         Texas, US

            ke9yq.ampr.org                  Chicago, Illinois, US

            k9iu.ampr.org                   Indiana, US

            wb9uus.ampr.org                 Illinois, US

               Having  experience of  different environments of  both high-
          speed and low-speed TCP/IP-based network, in terms of robustness,
          no  significant differences  is shown.  Furthermore, in  terms of
          hardware and  software  technology, although  most  packet  radio
          equipments  use late '80  microelectronics, it is  proven to be a
          reliable  and workable  solution to expose  remote areas  such as
          "Indonesia" into world wide computer information society.


          SUMMARY

               In  this paper, we  have reported  the efforts to  build the





          hardware and  software prototypes  to support the  development of
          packet  radio network  in  Indonesia as  well  as experiments  to
          explore  the  possibility  in  expanding the  capability  of  our
          current computer network  without having to  be dependent on  any
          single  data  communication service.  It has  been experimentally
          proven that  the  packet  radio  technology  is  a  reliable  and
          workable  solution to  built a  low cost  TCP/IP-based  wide area
          computer  network  to  support  the socio-economics  as  well  as
          science-technology development in Indonesia.
               The microelectronics technology used  in the packet radio is
          not  the state-of-the art technology such as FDDI and ISDN rather
          a  late '80 technology and,  thus, easier to  adopt and replicate
          the hardware and software prototypes to provide a self-support in
          the  development of TCP/IP-based  WAN. Furthermore,  unlike other
          capital  intensive information  technology such  as ISDN,  packet
          radio technology is more  low-profile and decentralized in nature
          which relies heavily on the  participatory actions of the member.
          This  enables  us  to  develop  a  low-cost TCP/IP-based  WAN  in
          Indonesia  without  having to  depend  entirely  on the  services
          provided  by any commercial data network. Since the total cost to
          operate as well  as to build  packet radio  network is much  less
          than that of maintaining connections via commercial data network,
          we are convinced that  this approach is favourable in  support of
          the  development of TCP/IP-based WAN in Indonesia. We wish to see
          Indonesia as part of the Internet in the next decades.


          ACKNOWLEDGEMENTS

               We  wish to  thank Robby  Soebiakto YB1BG  and Dwi  YB0QC to
          enable  us in  performing  experiments on  long distance  message
          deliveries  as well as for  exposing to the  Amateur Packet Radio
          Satellite (PACSAT). We wish to thank the University of Waterloo -
          Amateur  Radio  Club  VE3UOW  to  allow  the  author  to  perform
          experiments  in TCP/IP-based  packet radio  network. Furthermore,
          thanks to  Armein Langi VE4ARM, Suryono  YG1QN/N5SNN, Tony AH6BW,
          Marsudi  YC3MR, Roger  VE3RKS,  Ralph VE3EUK,  Peter VK3AVE,  Ron
          YC0DZA, Wirjono YC2BIE, Prof.  Chapman (University of Wisconsin -
          Madison),  Prof.  Iskandar  Alisyahbana  (ITB),   Dr.  Kusmayanto
          Kadiman  (PIKSI-ITB), Dr.  S. Nasserie  (ITB), Dr.  Adang Suwandi
          (ITB), the  members of ITB-ARC  and the  members at  PAU-Mikronet
          (pau-mikro@eeserv.ee.umanitoba.ca)  for  their valuable  comments
          and encouragements during the course of the work.
               The  financial supports  from  the Indonesian  Government as
          well  as the  Canadian  International  Development Agency  (CIDA)
          through Canadian  Bureau of  International  Education (CBIE)  are
          greatfully acknowledged.





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