Whats the difference between 1G, 2G, 3G wireless networking systems?

First, about cellular generations. First 1G service was based on a TDM voice infrastructure -- built around class x switches and 64 kbps slots. It had data, but circuit switched over a 64Kpbs voice bearer.

Second, 2G service had the same switched TDM backbone, but added a true Data Bearer and a digital voice bearer. Data rates were still limited to the max 64kbps of a single time slot.

2.5G added a packet bearer to the mix, still limited to 64kbps slots.

Third generation (3G) changed the backbone slightly to allow a full T1 or E1 or J1 to be consumed by a data sub-scriber, but is still based on an ISDN style backbone. Sure you have packet switched data, but its carried over a traditional TDM backbone. There still a circuit voice backbone and while the data rates are high enough for VoIP, the latency of the data service is to great to base all of the "bearer services" on it, so you still have circuit voice, circuit data and packet data bearers.

Finally, 4G systems will utilize a packet infrastructure rather than a traditional telephone architecture. Services will be horizontally layered on top of a proper low latency, QoS enabled packet switch (read IP) infrastructure. Gone will be the circuit voice and circuit data bearers.

So "G" has more to do with the infra-structure and less to do with the data rates. The data rates over the air are driven by the organization of the infrastructure and other than that have little to do with what generation they are.

In that sense, this NexTel trial is a 4G trial.
K A Solaman

Kerala School Kalosvam Manual-HSS-Grace marks!

PROCEEDINGS OF THE DIRECTOR, DIRECTORATE OF HIGHER
SECONDARY EDUCATION, HOUSING BOARD BUILDINGS, SANTHI
NAGAR, THIRUVANANTHAPURAM
Sub:- Higher Secondary Education – Higher Secondary Examination, March
2010 – Appendix 16 and Appendix 17 appended to Notification
partially modified – Orders issued – reg.
ORDER No. EX II (1) 53388/HSE/09 Dated: 20/01/2010
Read:- 1. Appendix 16 and Appendix 17 appended to Notification of Even
No. dated 27-10-2009.
2. Kerala School Kalosvam Manual, 2008
ORDER
In accordance with the norms stipulated in the Kerala School Kalolsavam
Manual, 2008 cited (2) the Appendix 16 (page 39) appended to Notification for the
Higher Secondary Examination, March 2010 is partially modified as detailed below.
(a) Grace marks are given to the winners in the State Level Higher
Secondary School Youth Festival as given below.
(1) A Grade - 30 Score
(2) B Grade - 24 Score
(3) C Grade - 18 Score
Grace marks will be awarded only after the Second Year Higher Secondary
Examination. It will be awarded only once even if a student gets eligible grade in State
Level Youth Festival twice, during the course of study.

►CSIR UGC NET New Exam Scheme for Single Paper From June 2011

CSIR-UGC (NET) EXAM FOR AWARD OF JUNIOR RESEARCH FELLOWSHIP AND ELIGIBILITY FOR LECTURERSHIP


EXAM SCHEME FOR SINGLE PAPER CSIR-UGC NET Exam
FROM June 2011

CSIR-UGC NET Exam for Science stream is conducted by CSIR in the following areas: -

1. Chemical Sciences
2. Earth Sciences
3. Life Sciences
4. Mathematical Sciences
5. Physical Sciences



It has been decided to introduce Single Paper MCQ MCQ (Multiple Choice Question) based test from June 2011 exam. The pattern for the Single Paper MCQ test shall be as given below:-

v The MCQ test paper of each subject shall carry a maximum of 200 marks.
v The exam shall be for duration of three hours.
v The question paper shall be divided in three parts

Ø Part 'A' shall be common to all subjects. This part shall be a test containing a maximum of 20 questions of General Science and Research Aptitude test. The candidates shall be required to answer any 15 questions of two marks each. The total marks allocated to this section shall be 30 out of 200

Ø Part 'B' shall contain subject-related conventional MCQs. The total marks allocated to this section shall be 70 out of 200. The maximum number of questions to be attempted shall be in the range of 25-35.

Ø Part 'C' shall contain higher value questions that may test the candidate's knowledge of scientific concepts and/or application of the scientific concepts. The questions shall be of analytical nature where a candidate is expected to apply the scientific knowledge to arrive at the solution to the given scientific problem. The total marks allocated to this section shall be 100 out of 200.

Ø A negative marking for wrong answers, wherever required, shall be @ 25%

* The new pattern shall be implemented from June, 2011 exam
* Model Question Papers in the new format shall be made available along with Notification for the June, 2011 exam.



PHYSICAL SCIENCES
EXAM SCHEME

TIME: 3 HOURS MAXIMUM MARKS: 200

From June, 2011 CSIR-UGC (NET) Exam for Award of Junior Research Fellowship and Eligibility for Lecturership shall be a Single Paper Test having Multiple Choice Questions (MCQs). The question paper shall be divided in three parts.

Part 'A'
This part shall carry 20 questions pertaining to General Science, Quantitative Reasoning & Analysis and Research Aptitude. The candidates shall be required to answer any 15 questions. Each question shall be of two marks. The total marks allocated to this section shall be 30 out of 200.

Part 'B'
This part shall contain 20 Multiple Choice Questions (MCQs) generally covering the topics given in the Part ‘A’(CORE) of syllabus. All questions are compulsory. Each question shall be of 3.5 Marks. The total marks allocated to this section shall be 70 out of 200.

Part 'C'
This part shall contain 25 questions from Part ‘B’(Advanced) that are designed to test a candidate's knowledge of scientific concepts and/or application of the scientific concepts. The questions shall be of analytical nature where a candidate is expected to apply the scientific knowledge to arrive at the solution to the given scientific problem. There will be 10 compulsory questions. Out of remaining 15 questions, a candidate shall be required to answer any 10. Each question shall be of 5 Marks. The total marks allocated to this section shall be 100 out of 200.

• There will be negative marking @25% for each wrong answer.

• To enable the candidates to go through the questions, the question paper booklet shall be distributed 15 minutes before the scheduled time of the exam. The Answer sheet shall be distributed at the scheduled time of the exam.

• On completion of the exam i.e. at the scheduled closing time of the exam, the candidates shall be allowed to carry the Question Paper Booklet. No candidate is allowed to carry the Question Paper Booklet in case he/she chooses to leave the test before the scheduled closing time.

• Model Question Paper shall be released at the time of Notification for June 2011 exam

CSIR-UGC National Eligibility Test (NET) for Junior Research Fellowship and Lecturer-ship
PHYSICAL SCIENCES
PART ‘A’ CORE
I. Mathematical Methods of Physics
Dimensional analysis. Vector algebra and vector calculus. Linear algebra, matrices, Cayley-Hamilton Theorem. Eigenvalues and eigenvectors. Linear ordinary differential equations of first & second order, Special functions (Hermite, Bessel, Laguerre and Legendre functions). Fourier series, Fourier and Laplace transforms. Elements of complex analysis, analytic functions; Taylor & Laurent series; poles, residues and evaluation of integrals. Elementary probability theory, random variables, binomial, Poisson and normal distributions. Central limit theorem.
II. Classical Mechanics
Newton’s laws. Dynamical systems, Phase space dynamics, stability analysis. Central force motions. Two body Collisions - scattering in laboratory and Centre of mass frames. Rigid body dynamics- moment of inertia tensor. Non-inertial frames and pseudoforces. Variational principle. Generalized coordinates. Lagrangian and Hamiltonian formalism and equations of motion. Conservation laws and cyclic coordinates. Periodic motion: small oscillations, normal modes. Special theory of relativity- Lorentz transformations, relativistic kinematics and mass–energy equivalence.
III. Electromagnetic Theory
Electrostatics: Gauss’s law and its applications, Laplace and Poisson equations, boundary value problems. Magnetostatics: Biot-Savart law, Ampere's theorem. Electromagnetic induction. Maxwell's equations in free space and linear isotropic media; boundary conditions on the fields at interfaces. Scalar and vector potentials, gauge invariance. Electromagnetic waves in free space. Dielectrics and conductors. Reflection and refraction, polarization, Fresnel’s law, interference, coherence, and diffraction. Dynamics of charged particles in static and uniform electromagnetic fields.
IV. Quantum Mechanics
Wave-particle duality. Schrödinger equation (time-dependent and time-independent). Eigenvalue problems (particle in a box, harmonic oscillator, etc.). Tunneling through a barrier. Wave-function in coordinate and momentum representations. Commutators and Heisenberg uncertainty principle. Dirac notation for state vectors. Motion in a central potential: orbital angular momentum, angular momentum algebra, spin, addition of angular momenta; Hydrogen atom. Stern-Gerlach experiment. Time-independent perturbation theory and applications. Variational method. Time dependent perturbation theory and Fermi's golden rule, selection rules. Identical particles, Pauli exclusion principle, spin-statistics connection.
V. Thermodynamic and Statistical Physics
Laws of thermodynamics and their consequences. Thermodynamic potentials, Maxwell relations, chemical potential, phase equilibria. Phase space, micro- and macro-states. Micro-canonical, canonical
and grand-canonical ensembles and partition functions. Free energy and its connection with thermodynamic quantities. Classical and quantum statistics. Ideal Bose and Fermi gases. Principle of detailed balance. Blackbody radiation and Planck's distribution law.
VI. Electronics and Experimental Methods
Semiconductor devices (diodes, junctions, transistors, field effect devices, homo- and hetero-junction devices), device structure, device characteristics, frequency dependence and applications. Opto-electronic devices (solar cells, photo-detectors, LEDs). Operational amplifiers and their applications. Digital techniques and applications (registers, counters, comparators and similar circuits). A/D and D/A converters. Microprocessor and microcontroller basics.
Data interpretation and analysis. Precision and accuracy. Error analysis, propagation of errors. Least squares fitting,
PART ‘B’ ADVANCED
I. Mathematical Methods of Physics
Green’s function. Partial differential equations (Laplace, wave and heat equations in two and three dimensions). Elements of computational techniques: root of functions, interpolation, extrapolation, integration by trapezoid and Simpson’s rule, Solution of first order differential equation using Runge-Kutta method. Finite difference methods. Tensors. Introductory group theory: SU(2), O(3).
II. Classical Mechanics
Dynamical systems, Phase space dynamics, stability analysis. Poisson brackets and canonical transformations. Symmetry, invariance and Noether’s theorem. Hamilton-Jacobi theory.
III. Electromagnetic Theory
Dispersion relations in plasma. Lorentz invariance of Maxwell’s equation. Transmission lines and wave guides. Radiation- from moving charges and dipoles and retarded potentials.
IV. Quantum Mechanics
Spin-orbit coupling, fine structure. WKB approximation. Elementary theory of scattering: phase shifts, partial waves, Born approximation. Relativistic quantum mechanics: Klein-Gordon and Dirac equations. Semi-classical theory of radiation.
V. Thermodynamic and Statistical Physics
First- and second-order phase transitions. Diamagnetism, paramagnetism, and ferromagnetism. Ising model. Bose-Einstein condensation. Diffusion equation. Random walk and Brownian motion. Introduction to nonequilibrium processes.
VI. Electronics and Experimental Methods
Linear and nonlinear curve fitting, chi-square test. Transducers (temperature, pressure/vacuum, magnetic fields, vibration, optical, and particle detectors). Measurement and control. Signal conditioning and recovery. Impedance matching, amplification (Op-amp based, instrumentation amp, feedback), filtering
and noise reduction, shielding and grounding. Fourier transforms, lock-in detector, box-car integrator, modulation techniques.
High frequency devices (including generators and detectors).
VII. Atomic & Molecular Physics
Quantum states of an electron in an atom. Electron spin. Spectrum of helium and alkali atom. Relativistic corrections for energy levels of hydrogen atom, hyperfine structure and isotopic shift, width of spectrum lines, LS & JJ couplings. Zeeman, Paschen-Bach & Stark effects. Electron spin resonance. Nuclear magnetic resonance, chemical shift. Frank-Condon principle. Born-Oppenheimer approximation. Electronic, rotational, vibrational and Raman spectra of diatomic molecules, selection rules. Lasers: spontaneous and stimulated emission, Einstein A & B coefficients. Optical pumping, population inversion, rate equation. Modes of resonators and coherence length.
VIII. Condensed Matter Physics
Bravais lattices. Reciprocal lattice. Diffraction and the structure factor. Bonding of solids. Elastic properties, phonons, lattice specific heat. Free electron theory and electronic specific heat. Response and relaxation phenomena. Drude model of electrical and thermal conductivity. Hall effect and thermoelectric power. Electron motion in a periodic potential, band theory of solids: metals, insulators and semiconductors. Superconductivity: type-I and type-II superconductors. Josephson junctions. Superfluidity. Defects and dislocations. Ordered phases of matter: translational and orientational order, kinds of liquid crystalline order. Quasi crystals.
IX. Nuclear and Particle Physics
Basic nuclear properties: size, shape and charge distribution, spin and parity. Binding energy, semi-empirical mass formula, liquid drop model. Nature of the nuclear force, form of nucleon-nucleon potential, charge-independence and charge-symmetry of nuclear forces. Deuteron problem. Evidence of shell structure, single-particle shell model, its validity and limitations. Rotational spectra. Elementary ideas of alpha, beta and gamma decays and their selection rules. Fission and fusion. Nuclear reactions, reaction mechanism, compound nuclei and direct reactions.
Classification of fundamental forces. Elementary particles and their quantum numbers (charge, spin, parity, isospin, strangeness, etc.). Gellmann-Nishijima formula. Quark model, baryons and mesons. C, P, and T invariance. Application of symmetry arguments to particle reactions. Parity non-conservation in weak interaction. Relativistic kinematics.

Makaravilakku heals millions

Truth or myth-Makaravilakku and Sabarimala heal many. Let it carry on. Sabarimala pilgrimage is a saunter into the Nature.

Keep open Sabarimala shrine on all days.

The stampede at the Sabarimala shrine in which 104 pilgrims have died indicates that human life is a commodity for Rs 5-6lakh. The money that received by the family of ill-fated pilgrims says we do not value human life that much. Lack of proper schedule for the travel of people to Sabarimala is the root cause of the grave mishap.

To avoid the heavy rush at Makaravilaku season why can’t Devaswom Board make arrangement for keeping the Sabarimala temple opened all the days in a year instead limiting it to 41 days or less. Why the heap of camphor burned at Ponnambalamedu on Makaravilaku day alone? Can’t it be performed a dozen days in a year on other holy days so that pilgrims get more opportunity for a healing thought by viewing it? Again worshippers hating large crowd could also advantageously visit Sabarimala at their pace if the temple is kept opened on all days.

Sabarimala is small area and that is not meant for for huge crowd. It is located at a remote hilly place where easy accessibility is difficult. The government has not provided scientific traffic management despite the huge sum received from the pilgrims as donation and travel fare.

It is better to have an introspection for the people of Kerala than accusing one and the other.

K A Solaman

The sky is the limit

The success or failure of a space mission depends on many factors. The probability of successfully launching a satellite can't be predicted. That's the reason not too many people are criticising the recent failure of the GSLV satellite. The scientists must focus on rectifying technical snags. More than Chandrayaan, India needs more space projects that improve our communication network facility. Chandrayaan can only fetch data already available with Nasa or
similar agencies.
KA Solaman, via email
The Hindustan Times, Jan 2, 2011