MOBILE DEFINITIONS :
G - I
GB (Gigabyte)
1GB is equal to approximately 1 billion bytes or exactly 1024 MB.
Gbps (Gigabits per second)
1 Gbps = 1024 Mbps. Gbps measures data transmission over a carrier.
Geo-tag
Geo-tagging is a function, where GPS-enabled devices can insert metadata with geographical information (coordinates) into a file such as photo, associating it with the geographic location it was taken at. Some new cameraphones support automatic geo-tagging of any pictures taken.
Geo-tags can be read by any device or desktop computer software which reads geo-tagging metadata, such as image editors and online image galleries.
GPRS
General Packet Radio Service is a packet-switching technology that enables data transfers through cellular networks. It is used for mobile internet, MMS and other data communications. In theory the speed limit of GPRS is 115 kbps, but in most networks it is around 35 kbps. Informally, GPRS is also called 2.5G.
GPS (Global Positioning System)
Global Positioning System was developed by the United States' Department of Defense. It uses between 24 and 32 Medium Earth Orbit satellites that transmit precise microwave signals. This enables GPS receivers to determine their current location, time and velocity. The GPS satellites are maintained by the United States Air Force.
GPS is often used by civilians as a navigation system. On the ground, any GPS receiver contains a computer that "triangulates" its own position by getting bearings from at least three satellites. The result is provided in the form of a geographic position - longitude and latitude - to, for most receivers, within an accuracy of 10 to 100 meters. Software applications can then use those coordinates to provide driving or walking instructions. Getting a lock on by the GPS receivers on the ground usually takes some time especially where the receiver is in a moving vehicle or in dense urban areas. The initial time needed for a GPS lock is usually dependent on how the GPS receiver starts. There are three types of start - hot, warm and cold.
The hot start is when the GPS device remembers its last calculated position and the satellites in view, the almanac used (information about all the satellites in the constellation), the UTC Time and makes an attempt to lock onto the same satellites and calculate a new position based upon the previous information. This is the quickest GPS lock but it only works if you are generally in the same location as you were when the GPS was last turned off.
The warm start is when the GPS device remembers its last calculated position, almanac used, and UTC Time, but not which satellites were in view. It then performs a reset and attempts to obtain the satellite signals and calculates a new position.
The receiver has a general idea of which satellites to look for because it knows its last position and the almanac data helps identify which satellites are visible in the sky. This takes longer than a hot start but not as long as a cold start.
And finally – the cold start is when the GPS device dumps all the information, attempts to locate satellites and then calculates a GPS lock. This takes the longest because there is no known information.
The GPS receiver has to attempt to lock onto a satellite signal from any available satellites, basically like polling, which takes a lot longer than knowing which satellites to look for. This GPS lock takes the longest. In an attempt to improve lock times, cellphone manufacturers and operators have introduced the Assisted GPS technology, which downloads the current ephemeris for a few days ahead via the wireless networks and helps triangulate the general user ’ s position with the cell towers thus allowing the GPS receiver to get a faster lock at the expense of several (kilo)bytes.
gpsONE
gpsOne is the brand name for a mobile GPS chipset manufactured by Qualcomm that allows mobile phones to lock a user ’ s position faster by using a technology referred to as A-GPS or Assisted-GPS.
gpsONEXTRA Assistance technology
Qualcomm's new gpsOneXTRA Assistance technology provides enhanced operation by enabling a user to download a small assistance data file through a brief Internet access session.
Network operators who have not yet deployed A-GPS systems can provide their subscribers with enhanced GPS performance on mobile handsets by using Qualcomm's gpsOneXTRA Assistance technology.
GPU (Graphics Processing Unit)
The GPU (Graphics Processing Unit) is a specialized circuit designed to accelerate the image output in a frame buffer intended for output to a display.
GPUs are very efficient at manipulating computer graphics and are generally more effective than general-purpose CPUs for algorithms where processing of large blocks of data is done in parallel.
Modern smartphones are equipped with advanced embedded chipsets that can do many different tasks depending on their programming. GPUs are an essential part of those chipsets and as mobile games are pushing the boundaries of their capabilities, the GPU performance is becoming increasingly important.
H.263
A video codec standard originally designed as a low-bitrate compressed format for videoconferencing. It has been widely adopted as the standard for video streaming over mobile networks.
Standard image sizes specified by H.263 include SQCIF (128 x 96 pixels), QCIF (176 x 144), and CIF (352 x 288) resolutions.
H.263 handles only the visual part of a video stream, the audio is encoded using audio encoders such as AMR.
Half-QWERTY keyboard layout
A keyboard layout similar to QWERTY but having two letters per key. The basic arrangement is the same, however the keyboard is narrower which makes it suitable for use with one hand and it fits more easily in the lower part of a bar-shaped device.
Predictive text is almost always used auto-suggest words allowing users to press a button only once.
Handwriting recognition
The ability of a device or software program to analyze the shape of cursive or printed handwriting drawn on a touchscreen and then translate it into letters, words, numbers, and punctuation marks.
Most devices that have touchscreens have built-in handwriting recognition capability. Input is best done using a stylus.
It should be noted that only devices using resistive type of touchscreen readily allows for input with various objects. The capacitive touchscreen devices can accept only human finger input.
Haptics
A category of technology that provides physical feedback when the user interacts with virtual things. This could be "pressing" a button on a touch screen or "feeling" the rough edge of the road in a racing game. The feedback is implemented as vibration.
Hot Spot
An area where users can access Wi-Fi services to access the Internet if they have the appropriate device. Hot
spots vary in area of coverage. They are usually public and many charge users by the day or month. However, some are free - for example privately owned in restaurants or cafes or public in universities and schools.
Hot Swap
Inserting or removing an external peripheral device (such as flash memory or hard drive) from a host (a mobile phone or desktop computer) while the host is still operating.
"Hot swappable" refers to a component's ability to be operated in such way. In mobile phones, this usually refers to the ability to insert or remove the memory card without switching off the
device.
HSCSD (High-Speed Circuit Switched Data)
A system for data calls on GSM networks that came before packet based systems such as GPRS and EDGE.
HSCSD is the "high-speed" variant of CSD (maximum speed of 9.6 kbps) that has better error-correction codes that give a boost in speed of about 50% and allows several call channels to be used as one - up to four channels - resulting in a maximum speed of 57.6 kbps. HSCSD was never widely adopted outside Europe.
HSDPA (High-Speed Downlink Packet Access)
An upgrade for UMTS networks that doubles network capacity and increases download data speeds by five times or more.
The service was initially deployed at 1.8 Mbps but upgrades to the networks and new user devices led to increased rates of 3.6 Mbps, followed by 7.2 Mbps.
HSDPA only handles the downlink while the uplink is handled by a related technology called HSUPA. The combination of both technologies is usually called HSPA.
HSP (Headset Profile)
A Bluetooth profile that enables wireless connection between a phone and a Bluetooth headset. It supports simultaneous two-way audio but not stereo. It is one of the most common profiles with only a small number of phones supporting only the similar handsfree profile.
HSP is used by other devices as well, a Bluetooth-enabled PC with VoIP software such as Skype for example.
HSUPA (High-Speed Uplink Packet Access)
An upgrade for UMTS/HSDPA networks that increases upload data speeds up to 5.76 Mbps. HSUPA together with HSDPA are sometimes referred to as HSPA. The standard is backwards compatible with UMTS and HSDPA and will work with devices supporting only those standards.
HSUPA only handles the uplink while the downlink is handled by a related technology called HSDPA.
HTML (Hypertext Markup Language)
A standard markup language used to create web pages.
It was designed with desktop computers in mind and web pages may have reduced usability when viewed on devices with smaller screens and limited input options (as is the case with most mobile phones). There is a newer format called XHTML that is better suited for mobile devices.
Hz (Hertz)
A unit of frequency measurement equal to one cycle per second.
iDEN (Integrated Digital Enhanced Network)
A TDMA based digital mobile network system. It was developed by Motorola, which remains the main manufacturer for iDEN devices. The main advantage of iDEN is the Push-To-Talk system, which enables mobile phones to be used as walkie-talkies.
Newer iDEN phones use a SIM card that is compatible with GSM phones for international roaming, but only a few phones support both standards.
IMAP (Internet Message Access Protocol)
An Internet protocol used by email clients to access messages from a server. IMAP is a newer alternative to POP3.
Unlike POP3, which only downloads the messages, IMAP synchronizes them with the email server and tracks changes in their status. Another feature of IMAP is that it allows messages to be organized by folders and the email client setup to use IMAP access will also synchronize the folders beside the emails themselves.
IMEI (International Mobile Equipment Identity)
IMEI is a unique 15-digit serial number that uniquely identifies a GSM or UMTS mobile phone. It consists of four parts and provides information, such as the manufacturer, to the mobile network. It is usually printed on the device under the battery.
IMEI can be used to "ban" a stolen phone, making it hard to use by the thief with a new SIM card.
IP (Internet Protocol)
IP is the the protocol used for communicating data across a packet-switched network used in most publicly accessible networks today. Connections that mobile devices make to GPRS, 3G and similar networks are made using IP.
IrDA (Infrared Data Association)
• A standard for transmitting data using an infrared port. Transfer speeds are roughly the same as traditional parallel ports.
• The industry group that created the IrDA technical standard.
Infrared connectivity is an old wireless technology used to connect two electronic devices. It uses a beam of infrared light to transmit information and so requires direct line of sight and operates only at close range. IR was superseded by Bluetooth, which has the advantage of operating at longer distances (around 30 feet) and
being omni-directional. Many home devices such as TVs and DVD players still use IR remote controls. Some smartphones are capable
of using their IR port to control these devises but that usually requires third-party software.
