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					                  High-Speed Downlink Packet Access



High-Speed Downlink Packet Access (HSDPA) is a protocol and cell phone technology is
sometimes            referred          to            as            3.5            G.

HSDPA is an evolution of W-CDMA standard and is designed to improve data transfer speed of
5x higher. HSDPA channel memdefinisikan a new W-CDMA, the high-speed downlink shared
channel (HS-DSCH) that mode of operation is different from W-CDMA channels that exist today.
Until now the use of technology to HSDPA only under the direction of communication to the
mobile                                                                               phone.

Speed                                      data                                       download

   In the neighborhood of this technology can perform data download speed up to 3.7 Mbps.
   In case of moving a person who was driving at highway speed of 100 km / h speed Internet
access                          to                         1.2                         Mbps.
   In a crowded office environment users can enjoy streaming video with an approximate speed
of                                          300                                         Kbps.

Excess                                                                                   HSDPA

Provide a faster feedback when users use interactive applications such as mobile office or high-
speed Internet access to use the facility to download a game or audio and video. Another
advantage HSDPA, increase system capacity without requiring additional frequency spectrum.
This    leads     to   reduced    costs     of     mobile     data     services   significantly.

High-Speed Downlink Packet Access (HSDPA) is a network dedicated to mobile phones are
popular with a 3.5 G technology This technology provides the ability to download the fast and
the connection of asynchronous digital Subscriber line (ADSL) which is used in connection
internet service to residential areas and prevent the slowdown in mobile phone.
 History

In early 1978 the advent of technology the first generation (1G), the first technology that
launched the Global System for Mobile (GSM) and Code Division Multiple (CDMA). Access
method used by the CDMA and GSM are different, namely 1G can be used only to call and still
use monophonic ringtones, which certainly do not have access to the internet. Later in the
1990s launched the second generation technology (2G), which is GSM with facilities and new
polyphonic settings color variations. After 2G, 2.5G cell phone appears to have had features of
Mobile Multimedia Message (MMS) and has access to General Packet Radio Service (GPRS).
Rapid technological developments, so there was counterposed the mobile phone technology
with third-generation (3G). The technology is quite popular in the community, with one of the
advantages of the new mobile phone that features a video call which allows us to see the other
person when making a call. To date have been issued so-called 3.5G technology, which is a
broadband data transmission technology (bandwidth) that can be used to move (mobile
broadband)      and     based      High-Speed      Downlink     Package     Access    (HSDPA).

HSDPA was first introduced in Japan (a + 3G to 3.5G). 3.5 G technology is always evolving as the
previous generation. 3.5G is a continuation of the 3G technology which in theory provide voice,
video, and access at speeds up to 3.6 Mbps or nine times faster than 3G services generally.
Content itself is not much different from the content of the 3G technology already offered by
several mobile operators in Indonesia, namely a video call, mobile video, mobile TV and video
content. While the difference between 3.5G 3G 3.5G is presenting a much sharper picture than
the picture offered by 3G. As with earlier technologies, 3.5G technology is also used to provide
access to broadband or faster internet connection and direct connection to the Internet
network                      locally                     and                      internationally.
 Description

HSDPA has two phases, first phase capacity of 4.1 Mbps and then following a second phase with
a capacity of 11 Mbps and a maximum capacity of downlink peak data rate of up to 14 Mbps.
WCDMA technology was developed from the same as CDMA2000 EV-DO develop. HSDPA
networks provide an evolutionary path for Universal Mobile Telecommunications System
(UMTS) which allows for the use of larger data capacity is estimated at 14.4 Mbps for data
downloads and 2Mbps for uploads data. Released by the recent pace of this technology is
HSPDA +, with download speeds reaching 42 Mbps and 84 Mbps in the ninth release of the
3GPP                                                                                standard.

For HSDPA, internet access services that are new, High-Speed Downlink Shared Channel (HS-
DSCH), was added to the W-CDMA Release 5 and further specifications. This is done by
introducing three new physical layer channels: HS-SCCH, HS-DPCCH and HS-PDSCH. High Speed-
Shared Control Channel (HS-SCCH) informs the user that the data will be transmitted on the HS-
DSCH 2 slots ahead. Uplink High Speed-Dedicated Physical Control Channel (HS-DPCCH) carries
acknowledgment information and current channel quality indicator (CQI) of the user. This value
is then used by the base station to calculate how much data to send to the user device to the
next transmission. High Speed Downlink Shared Channel-Physical (HS-PDSCH) is mapped to
channel HS-DSCH transport channel on which to bring the actual user data.
 Fast                                Scheduling                                Package

HS-DSCH downlink channel is shared between users using channel-dependent scheduling to
make use of available radio signal to the maximum. Any user of this technology device
continuously transmits a downlink signal quality indication, which is 500 times per second.
From the information obtained from any device, base station decides which users will be sent
the data to the frame 2 ms on the next data flow and how much data should be sent to any
user or users. Larger data can be sent to users who have high downlink signal quality.

The number of shares of the series code and the network bandwidth, allocated to users
through the provision of HDSPA network itself. The allocation is done is "semi-static", but in it
can still be modified when the network is operating, but not in a per frame basis. This allocation
represents a trade-off between bandwidth allocated to users HDSPA. It is intended for the
allocation of the sound wave and non-HDSPA data users. Clearly, this allocation is a unit of the
division of code for deployment on 16 factors, of which 16 exist and up to 15 can be allocated
to the HSDPA network. When the base station is selected, the next step is to determine which
users will receive data on the next frame. It can also be useful to determine the distribution of
the code to be used for each user. This information is sent to user devices via one or more
"scheduling channels". Channel is not part of the HSDPA network is predetermined, but it is a
network that has been allocated separately. Further, to provide a 2 ms frame, data may be sent
repeatedly premises using a different code-sharing. Maximum number of users to receive data
in a given 2 ms frame, diapa seen from the large number of allocations in the distribution of the
code. For example, in CDMA2000 1xEV-DO technology, data is sent only to a single user in a
time                                                                                        series.
 Security

Authenticate a user or users of HSDPA technology is done from the SIM card (or RUIM). Data
from the user will be encoded differently according to the CDMA standard, and works much
better than the cryptographic algorithm. The safety of this technology will be broken if there is
an intruder who entered the base station or when an intruder is to get a channel code that can
only come from a special agent (6432). In other words, security of ownership of this access is
guaranteed.
 HSDPA                                                                                   Modem

In the smartphone, a very fast internet access can be taken from a cell phone antenna itself to
be processed further. As for the laptop or netbook, the computer may not be able to capture
and process the signals are there, mostly just to catch the signal via Wi-Fi or Bluetooth. Solution
that can be offered is to use a modem, by way of picking up signals from an antenna that is
separate and further processed so that the computer can be connected to the internet access
of                                        modem                                             signals.

HSDPA USB modem can be used to get internet connection on your home computer where
there is a strong signal from the HSDPA. This will replace the need for fixed line users will
connect.
 Excellence

  HSDPA technology can be used for multiple users simultaneously. But if all the user to
download a file with a large capacity of the internet, will impact on the flow of data, which all
users            will              have              a              slow             connection.
  Frequencies used by this technology has been able dimaksimalisasikan efficiently with the
use           of           bandwidth             (bandwidth)            is          appropriate.
  Reduce delays in downloading or download data (delay), even with the many users of the
HSDPA connection, downloads the data will not be delayed, but may experience some delays
the                           flow                             of                          data.

Shortage

  The maximum speed of 14.4 Mbps in a distance of less than 1 km from the base station.
When it reaches a distance of more than equal to 6 km, the data flow will decrease the speed of
1                                                                                        Mbps.
  The price is quite expensive when compared with networks such as WiMAX.

				
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posted:3/27/2012
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