Functions of BSC :

Functions of BTS

Introduction to EVDO,

EV-DO, 1xEvDO and 1xEV-DO, is a standard for high speed wireless broadband. The acronym is short for “Evolution, Data Only” or “Evolution, Data Optimized”. It is one of two major Third Generation, or 3G, wireless standards. The competing standard is known as W-CDMA.  EVDO is an advanced CDMA technology developed by Qualcomm to deal with this limitation. EVDO uses the same approach used for the internet. IP, the Internet Protocol, breaks data into small pieces called packets. Each packet is sent independently of all the other packets. This saves bandwidth for use by other devices; when neither party on a phone call is speaking, the connection consumes no bandwidth because there are no packets to send. or, when an internet web site is accessed, no bandwidth is used until the site starts sending the web page.EVDO has a theoretical throughput of 2.4 megabits per second. A significant advantage of EVDO over competing technologies is that it uses the same broadcasting frequencies as existing CDMA networks.

I) EVDO, also known as CDMA2000, is CDMA’s answer to the need for speed with a downstream rate of about 2 megabits per second, though some reports suggest real world speeds are closer to 300-700 kilobits per second (Kbps). This is comparable to basic DSL. As of fall 2005, EVDO is in the process of being deployed. It is not available everywhere and requires a phone that is CDMA2000 ready.

II) GSM’s answer is EDGE (Enhanced Data Rates for GSM Evolution), which boasts data rates of up to 384 Kbps with real world speeds reported closer to 70-140 Kbps. With added technologies like UMTS (Universal Mobile Telephone Standard) and HSDPA (High Speed Downlink Packet Access), speeds  reportedly increase to about 275–380 Kbps. This technology is also known as W-CDMA, but is incompatible with  CDMA networks. An EDGE-ready phone is required.

III) In the case of EVDO, theoretical high traffic can degrade speed and performance, while the EDGE network is more susceptible to interference. Both require being within close range of a cell to get the best speeds, while performance decreases with distance. 1xEV-DO is an enabling technology for wireless Internet services. The following are the key aspects of the standard:

• • Supporting data rates of up to 2.4 Mbps
• • Having no backward-compatibility with CDMA 2000
• • Including two inter-operable modes: an integrated 1x mode optimized for voice and medium data speeds, and a 1xEV mode optimized for non real-time high capacity/high speed data and Internet access

• • Providing Adaptive Rate Operation with respect to channel conditions
• • Providing Adaptive modulation and coding
• • Providing Macro diversity via radio selection
• • Providing an always-on operation of 1xEV-DO terminals in the active state
• • Using a multi-level modulation format (QPSK, 8-PSK, 16-QAM)

1x EV-DV:

1xEV-DV is a CDMA-based 3G standard for the Air Interface. 1xEV-DV is the second phase of evolution of CDMA 2000 and offers complete backward compatibility with CDMA 2000. 1xEV-DV is also compatible with the ANSI-41 core network standards.

EVDO Booster Antenna

If you are in the fringe area of EVDO and coverage is spotty, or you are in a weaker signal area, consider an EVDO external booster antenna. This antenna plugs into the PC 5220 Card / Novatel V620 / KPC650 / Sierra AirCard 580 Card and improves performance dramatically. It will increase your signal strength which will give you a much faster  throughput. The external antenna is about twice the size of the PC Card. Do not get a Booster Antenna that clips on to the current antenna – get one that plugs directly into the external antenna port that is built-into the EVDO cards. When you plug in an external antenna through the antenna port, the built-in antenna is disabled and you only use the external and get much better performance.

List of Abbreviations:

1xEV-DO 1x Evolution of Data Only

1xEV-DV 1x Evolution of Data and Voice

3GPP Third Generation Partnership Project

AAA Authentication,Authorisation, and Accounting

AN-AAA Access Network – AAA

ARQ Automatic Repeat Request

ATM Asynchronous Transfer Mode

BLOB Block of Bits

BPSK Binary Phase Shift Keying

BRAN Broadband Radio Access Networks

BS Base Station

CLI Command Line Interface

CRC Cyclic Redundancy Code

DSP Digital Signal Processor

DTX Discontinuous Transmission

DSSS Direct Sequence Spread Spectrum

EDGE Enhanced Data rate for global Evolution

EIB Erasure Indicator Bits

FA Foreign Agent

F-CCCH Forward Common Control Channel

FPGA Field Programmable Gate Array

HA Home Agent

HSDPA High Speed Downlink Packet Access

LAC Link Access Protocol

LTU Logical Transmission Unit

MAC Medium Access Control

MAC-I Message Authentication Code for Integrity

MCSB Message Control and Status Block

OFDM Orthogonal Frequency Division Multiplexing

PCF Packet control Function

PCI Peripheral Component Interconnect

PDCCH Packet Data Control Channel

PDCH Packet Data Channel

PDCHCF Packet Data Channel Control Function

PDSN Packet Data Serving Node

PDU Protocol Data Unit

PN Pseudo Noise

QIB Quality Indicator Bits

Q-PCH Quick Paging Channel

QPSK Quadrature Phase Shift keying

RLP Radio Link Protocol

RSVP Resource Reservation Protocol

SDU Service Data Unit

SO Service Option

SPID Sub Packet Identifier

SSD Shared Secret Data

UMTS Universal Mobile Telecommunications System

W-CDMA Wide Code Division Multiple Access

WLAN Wireless Local Area Network

General Bluetooth Interface Characteristics:

• Operates in the 2.4 GHz band.

• Uses Frequence Hop (FH) spread spectrum, which divides the frequency band into a number of hop channels. During a connection, radio transceivers hop from one channel to another in a pseudo-random fashion.

• Supports up to 8 devices in a piconet (two or more Bluetooth units sharing a channel).

• Built-in security.

• Non line-of-sight transmission through walls and briefcases.

• Omni-directional.

• Supports both isochronous and asynchronous services; easy integration of TCP/IP for networking.

• Regulated by governments worldwide.

Bluetooth is intended to be a standard that works at two levels:

1.It provides agreement at the physical level — Bluetooth is a radio-frequency standard.

2.It also provides agreement at the next level up, where products have to agree on when bits are sent, how many will be sent at a time and how the parties in a conversation can be sure that the message received is the same as the message sent.

Bluetooth Frequency & Power:

Bluetooth interface communicates on a frequency of 2.45 gigahertz, which has been set aside by international agreement for the use of industrial, scientific and medical devices (ISM).

It radiates signal by sending out very weak signals of 1 milliwatt by this way Bluetooth devices avoid interfering with other systems . The low power limits the range of a Bluetooth device to about 10 meters .

Bluetooth working

Bluetooth uses a technique called spread-spectrum frequency hopping. In this technique, a device will use 79 individual, randomly chosen frequencies within a designated range, changing from one to another on a regular basis.

In the case of Bluetooth, the transmitters change frequencies 1,600 times every second, meaning that more devices can make full use of a limited slice of the radio spectrum. Since every Bluetooth transmitter uses spread-spectrum transmitting automatically, it’s unlikely that two transmitters will be on the same frequency at the same time. This same technique minimizes the risk that portable phones or baby monitors will disrupt Bluetooth devices, since any interference on a particular frequency will last only a tiny fraction of a second.

When Bluetooth-capable devices come within range of one another, an electronic conversation takes place to determine whether they have data to share or whether one needs to control the other. The user doesn’t have to press a button or give a command — the electronic conversation happens automatically. Once the conversation has occurred, the devices — whether they’re part of a computer system or a stereo — form a network.

Bluetooth systems create a personal-area network (PAN), or piconet, that may fill a room or may encompass no more distance than that between the cell phone on a belt-clip and the headset on your head. Once a piconet is established, the members randomly hop frequencies in unison so they stay in touch with one another and avoid other piconets that may be operating in the same room. Each piconet hops randomly through the available frequencies, so all of the piconets are completely separated from one another

Bluetooth Specifications:

• The devices in a piconet share a common communication data channel. The channel has a total capacity of 1 megabit per second (Mbps). Headers and handshaking information consume about 20 percent of this capacity.

• In the United States and Europe, the frequency range is 2,400 to 2,483.5 MHz, with 79 1-MHz radio frequency (RF) channels. In practice, the range is 2,402 MHz to 2,480 MHz. In Japan, the frequency range is 2,472 to 2,497 MHz with 23 1-MHz RF channels.

• A data channel hops randomly 1,600 times per second between the 79 (or 23) RF channels.

• Each channel is divided into time slots 625 microseconds long.

• A piconet has a master and up to seven slaves. The master transmits in even time slots, slaves in odd time slots.

• Packets can be up to five time slots wide.

• Data in a packet can be up to 2,745 bits in length

• There are currently two types of data transfer between devices: SCO (synchronous connection oriented) and ACL (asynchronous connectionless).

• In a piconet, there can be up to three SCO links of 64,000 bits per second each. To avoid timing and collision problems, the SCO links use reserved slots set up by the master.

• Masters can support up to three SCO links with one, two or three slaves.

• Slots not reserved for SCO links can be used for ACL links.

• One master and slave can have a single ACL link.

• ACL is either point-to-point (master to one slave) or broadcast to all the slaves.

• ACL slaves can only transmit when requested by the master

Advantages of Bluetooth Interface:

• Bluetooth provides flexible network that allows up to eight devices to share information.

• The network architecture allows one to add or remove nodes without additional infrastructure involved.

• The size of the implementation is small.

• Power consumption is small.

• It has the support of the security consideration like ‘Encryption’.

Here is the list of latest mobile number codes for India.List has been updated till 28/08/2011 as per the mobile number codes allotted by Department of Telecom, India.This list also contains the latest 5 digit series allotted to different telecom service providers.

Please Note:

1. This information will not be correct if the subscriber has ported out.

2.There may be some errors please use information carefully, let me know if there is any wrong entry.

FOR BETTER VISIBILTY JUST CLICK ON THE  GIVEN IMAGE OR YOU CAN SAVE THE IMAGE ALSO.

If you like this information please share it with others.

Lawful interception (LI) is obtaining communications network data pursuant to lawful authority for the purpose of analysis or evidence. Such data generally consist of signalling or network management information and/or the content of the communications.

Almost all countries have LI capability requirements and have implemented them using global LI requirements and standards developed by the European Telecommunications Standards Institute (ETSI), 3rd Generation Partnership Project (3GPP), or Cable Labs organizations – for wire line/Internet, wireless, and cable systems, respectively.

List of law enforcement agencies in India:

1.Intelligence Bureau:
2. Narcotics Control Bureau:
3. Directorate of Enforcement:
4. Central Economic Intelligence Bureau:
5. Directorate of Revenue Intelligence:
6. Central Bureau of Investigations:
7. Director General of Police, for respective States/ Union Territory.
8. Special Commissioner of Police, Special Cell, New Delhi (only for Delhi Metro
City Service Area).
9. Dy. Director General Signal Intelligence: HQ northern Command, Udhampur.
C/056 APO.
10. Dy. Director General Signal Intelligence: C/O HQ Eastern Command, Fort
William, Kolkata
11. National Investigation Agency:

GSM Handover

The user movements can produce the need to change the channel or cell, specially when the quality of the communication is decreasing. This procedure of changing the resources is called handover. Four different types of handovers can be distinguished:

• Handover of channels in the same cell.
• Handover of cells controlled by the same BSC.
• Handover of cells belonging to the same MSC but controlled by different BSCs.
• Handover of cells controlled by different MSCs.

Handovers are mainly controlled by the MSC. However in order to avoid unnecessary signalling information, the first two types of handovers are managed by the concerned BSC (in this case, the MSC is only notified of the handover).

The mobile station is the active participant in this procedure. In order to perform the handover, the mobile station controls continuously its own signal strengh and the signal strengh of the neighboring cells. The list of cells that must be monitored by the mobile station is given by the base station. The power measurements allow to decide which is the best cell in order to maintain the quality of the communication link. Two basic algorithms are used for the handover:

1.The `minimum acceptable performance’ algorithm. When the quality of the transmission decreases (i.e the signal is deteriorated), the power level of the mbbile is increased. This is done until the increase of the power level has no effect on the quality of the signal. When this happens, a handover is performed.

2.   The `power budget’ algorithm. This algorithm performs a     handover, instead of continuously increasing the power level, in order to obtain a good communicatio.

Types of GSM service

The ETSI Standards define the telecommunication services in the same way as ISDN (Integrated Services Digital Network) does. Different types of services are distinguished: bearer services, tele-services and supplementary services.

Bearer services:

Bearer services are telecommunication services providing the capability of transmission of signals between access points (called user-network interfaces in ISDN). The bearer services describe what the network can offer (e.g. speech, data and fax).

Teleservices:

Teleservices are telecommunication services including terminal equipment functions, that provide communication between users according to protocols established by agreement between network operators. The teleservices are user end-to-end services (e.g. emergency call and short message service).

Supplementary services:

Supplementary Services modify or supplement a basic telecommunication service. Consequently, they cannot be offered to a customer as a stand-alone service. They must be offered together or in association with a basic telecommunication service. The same supplementary service may be applicable to a number of telecommunication services. Most supplementary services are directly inherited from a fixed network, with minor modifications (when needed) to

adapt to mobility. Examples of supplementary services are calling line identification and call waiting.

Problem: I switched ON the receiver ,I Got “First setup” screen and I pressed OK.Signal Quality is shown as “good”.But ,STB Failed to find any channels and showed “Type (2) Error”.

Solution: Sometimes your dish catches signal of other than your DTH service provider, its strange but true, by virtue of which STB shows good signal quality. What you have to do is just try to readjust your dish (remember you get “good” signal indication on STB after making adjustment) then press ok. Now your STB should find new channels and call customer care to refreash your smart card. If  it is still giving error type (2)  then retry the steps mentioned above. It is hit and trial method because otherwise you need proper testing instrument to check the signal at the required frequecny.

Please give your feedback after doing this.

Do you wish to block commercial communications ? Then you register your preference with your Service Provider either by way of voice call or SMS to toll free number 1909.
For blocking the commercial communication You can register either in the
(a) Fully Blocked category; or in the
(b) Partially Blocked category
3. If you do not to want to get any commercial communication on your
phone either by way of voice or SMS, please register in the Fully Blocked
category;
4. Please register in the Partially Blocked category, if you wish to get
commercial communications in the form of SMS in respect of any or all
or some of the following seven subjects:
1. Banking/Insurance/Financial products/Credit cards,
2. Real Estate,
3. Education,
4. Health,
5. Consumer goods and automobiles,
6. Communication/Broadcasting/Entertainment/IT,
7. Tourism and Leisure.
Please note that in the Partially Blocked category, you will not receive any
commercial communications in the form of voice calls.
If you are already registered in the National Do Not Call Registry (NDNC) you do not have to re-register; your registration will continue under the ‘Fully Blocked’ category.
You may make a change in your preference at any point of time after expiry of three months from the date of registration or three months from the date of last change request. The service provider will confirm the registration of such a request within 24 hours to you through SMS, subject to the correctness of request. In case of errors in request, access provider will advise you to make a fresh request. You may make a request for withdrawal of your registration from National Customer Preference Register, at any time after expiry of three months from the date of registration. The service provider will delete your number from the Provider Customer Preference Register inform you of the withdrawal of your registration through SMS within 24 hours, subject to correctness of such request. No amount shall be charged from you for registration or change of preference or de-registration.
In case you receive an unsolicited commercial communication after expiry of seven days from the date of your registration in the Provider Customer Preference Register, you may make a complaint to your Access Provider, through voice call or SMS. The complaint has to be registered from the telephone number on which the unsolicited commercial
communication has been received. Your complaint should be made within three days of receipt of the unsolicited commercial communication. In such complaints, please mention the particulars of the telemarketer, the telephone number from which the unsolicited commercial communication has originated, the date, time in 24 hrs format and brief
description of such unsolicited commercial communication. The customer complaint registration facility is toll free and telephone number for the same is 1909. The complaint will be acknowledged with a unique complaint number provided by access provider immediately.
The access provider shall take appropriate action on the complaint and inform you about its resolution within seven days, subject to the correctness of the complaint.