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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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