GPRS

General Packet Radio Service (GPRS) is a data service that supplements other data services such as Circuit Switched Data (CSD, used for data and fax calls on GSM networks) and Short Message Service (SMS). The design of GPRS was informed by the fact that wireless data communications are bursty in nature. That is, the data is not sent in one long stream, but rather in short bursts. Traditional use of CSD such as the Wireless Application Protocol (WAP) for data transfer requires establishing connections between two communicating parties, which occupies bandwidth even when not transmitting data. With GPRS, data is sent as packets as and when required. This feature allows devices to stay connected all the time, and eliminates the need to establish a connection and stay connected within the entire duration. This allows service providers to bill customers based on the data transferred and not the connection time.

GPRS and 3G

3G wireless (or Third-Generation wireless) is an initiative to provide enhanced voice, text, and data services. The main draw of 3G networks is the vastly increased data transfer rate of between 384 Kbps and 2 Mbps. With these speed improvements, applications that support real-time video and high-quality multimedia elements can be deployed.

However, deploying 3G networks is not an overnight affair. This requires heavy investment from wireless carriers as well as from telephone and modem manufacturers. In the midst of waiting for the next generation wireless networks, GPRS bridges the gap between the current 2G networks (such as GSM or TDMA) and the forthcoming 3G networks. As such, GPRS is commonly known as 2.5G.

3G networks will likely be using W-CDMA (Wideband Code Division Multiple Access) technology, which is backed by industry giants like Nokia and Ericsson. In Europe, UMTS (Universal Mobile Telephone Service) has been adopted as a 3G network.

How GPRS Works?

GPRS uses multiple timeslots for sending data. In theory, GPRS can use up to eight timeslots, but physical constraints (such as the number of users currently on the network as well as the coverage quality) have placed the number to a maximum of five, with one or two timeslots reserved for upstream communications (leaving three or four for downloads).

There are altogether four encoding schemes used in a GPRS network. Their data rate per timeslot as well as their maximum data speed for eight timeslots. The encoding scheme to be used is determined by the service provider and depends on factors such as the quality of the channel (the radio link between the GPRS device and the base station). CS-1 has the highest reliability (but the lowest data rate) and CS-4 has the least reliability (but the highest data rate).

GPRS devices fall into three categories:

Class A

Class A devices can connect to GSM and GPRS services simultaneously, and both can work at the same time. This is the ideal communication device.

Class B

Class B devices can connect to either GSM or GPRS services (or both at the same time). But only one can work at a time. An example of Class B device is a GPRS-enabled mobile phone such as the Ericsson T68i. You may be using the GPRS service and suddenly a voice call comes in. You can use either the voice service or the GPRS service, but not the two simultaneously. Most mobile phones today are Class B devices.

Class C

Class C devices can connect to GSM or GPRS services (but not both at the same time). The user must manually switch between the two services. An example of Class C device is the Nokia D211 GPRS card. You need to manually switch between GSM and GPRS services.

Registry Keys and Values

A key can contain one or more values. Following are the five primary data types of values in the Registry:

REG_SZ (String value)
This data type is easy to understand and edit because it is made up of plain text and numbers. It is one of the most common data types in the Registry. The value for DoubleClickSpeed, mentioned earlier , is of this type.

REG_MULTI_SZ (String array value)
This data type contains several strings of plain text and numbers. The Registry Editor will let you edit these values, but it won’t let you create them.

REG_EXPAND_SZ (Expanded string value)
This data type contains variables that Windows uses to point to the location of files. For example, to point to the location of the Luna theme file, the expanded string value in the Registry is %SystemRoot%\resources\Themes\Luna.theme.

REG_BINARY (Binary values)
This data type is made up of binary data: 0s and 1s. As a general rule, you won’t edit binary values—instead you’ll edit string values because they’re made up of text and numbers,

REG_DWORD (DWORD values)
This data type is represented as a number. Sometimes a 0 turns on the key or 1 turns off the key, though it can use other numbers as well. While you see and edit the value as a number, such as 456, the Registry itself views the number as a hexadecimal number, 1C8.

Registry Hives & functions

HKEY_CLASSES_ROOT
This hive contains information about file types, filename extensions, and similar information. It instructs XP how to handle every different file type and controls basic user interface options, such as double-clicking and context menus. This hive also includes class definitions (hence the word “CLASSES” in its name) of unique objects, such as file types or OLE objects. Frequently, classes associated with file types contain the Shell subkey, which defines actions, such as opening and printing, that can be taken with that file type.

HKEY_CURRENT_USER
This hive contains configuration information about the system setup of the user that is currently logged into XP. It controls the current user’s Desktop, as well as XP’s specific appearance and behavior for the current user. This hive also manages network connections and connections to devices such as printers, personal preferences such as screen colors, as well as security rights. Also included in this hive are Security Identifiers (SIDs), which uniquely identify users of the PC and which have information about each user’s rights, settings, and preferences.

HKEY_LOCAL_MACHINE
This hive contains information about the computer itself, as well as about the operating system. It includes specific details about all hardware, including keyboard, printer ports, storage—the entire hardware setup. In addition, it has information about security, installed software, system startup, drivers, services, and the machine’s specific XP configuration.

HKEY_USERS
This hive contains information about every user profile on the system.

HKEY_CURRENT_CONFIG
This hive contains information about the current hardware configuration of the system, in the same way that HKEY_CURRENT_USER contains information about the current user of the system.

Install Windows 2000 without supplying the CD key

You can configure W2K to install without having to manually enter the CD key during the setup process.

First, you want to copy your Windows 2000 setup files from your CD to your hard drive. You have to copy at least the I386 directory.

Now go into the I386 directory you just copied onto your hard drive and look for a file called setupp.ini.

Right click it, select Properties, and remove the Read-only checkmark. Now open the file to edit it.

Your setupp.ini file should read something like this:

[Pid]
ExtraData=6166656C736263737373B2574A0581
Pid=51873XXX

Replace the XXX (generally it’ll be three zeros) at the end with “270”. It should now read something like this:

[Pid]
ExtraData=6166656C736263737373B2574A0581
Pid=51873270

Now you can now install Windows 2000 without a serial number!

You should remember that doing this might be considered illegal in Microsoft’s eyes so as such it’s not something I would recommend to do.

Install MS Office without supplying the CD key

Heres how to do it

Copy all files of your MS office CD to the hard disk.

Find a file called Setup.ini (which is found in the \FILES\SETUP subfolder). Right click the file, select Properties, and remove the Read-only checkmark. Now open the file to edit it.

Inside the file setup.ini, should be like this

[Options]
; The option section is used for specifying individual Installer Properties.
;USERNAME=customer
;COMPANYNAME=company info
;INSTALLLOCATION=C:\Program Files\MyApp

In the USERNAME section enter the registered owner’s name, do so also for the COMPANYNAME value.

Make sure you remove the “;” from the beginning of the lines (“;” means comment)

Now, add a following line to the [Options] section:

PIDKEY=ABCDEFGHIJKLMNOPQRSTUVWXY

NOTE: Use your own CD key, the above string is just an example (you wouldn’t believe the number of e-mails people actually send me telling me that the tip doesn’t work…)

(25 characters from your CD key, without the “-” seperation)

It should now read something like this:

[Options]
; The option section is used for specifying individual Installer Properties.
USERNAME= customer
COMPANYNAME=company info
;INSTALLLOCATION=C:\Program Files\MyApp
PIDKEY=ABCDEFGHIJKLMNOPQRSTUVWXY

NOTE: Use your own CD key, username, and company info.

Save the setup.ini file, burn the whole folder that contains the installation files to CD.

Now you can now install Office without needing to supply a CD key during the setup process!