What is 5G ?

It is a mobile broadband system that will provide higher performance than is available today’s most advanced 4G networks.  These performance improvements will be measurable in terms of speed, latency, reliability, scale and openness.  The 5G system will achieve this higher performance by integrating many new devices over multiple wireless technologies with new management and orchestration systems.  A 5G system will include existing and new technologies such as: LTE, new radio technology, highly variable end devices especially for M2M, virtualized software and management and orchestration systems.  There will be a single global 5G standard to ensure global coverage.  It will be deployed in commercial service by 2020, but components may be ready earlier. 

The main focus is now on research where evolution of existing technologies is on-going in parallel with innovation of new technologies. A lot of research is done in cooperation with universities and partners. By join forces, we can together understand the new use cases and the new requirements that will be put on 5G.

Pre-standardization and technology development will be on-going until 2017. Standardization activities to set the requirements and make 5G a global standard starts at 2017. In parallel, trials and test systems will be up and running. First commercial system will most likely be deployed by 2020.

   Requirements on 5G

The exact performance levels and requirements that systems and equipment will need to meet to label themselves 5G are yet to be defined by the International Telecommunication Union (ITU). This will take place somewhere around 2016-2018.

At this stage, we are using expectations levels that where set in the METIS project*). These expectations are:

·         Handle 1000 times the mobile data traffic of today

·         Billions of connected devices

·         100 times user data rates

·         Latency reduced by up to a factor of 5

·         10 times the battery life

·         Different devices: from mobiles, tablets and wearables, to cars, trucks, bikes, cereal packets… anything

·         Data integrity 

Resignation Letter sample

Samaple -01

Dear Sir,
I submit this letter of resignation and will be leaving my position from XXXX( Engineer/manager) with Company name  effectively on DD-MM-YEAR.
It has been a pleasure working for Company name  . During this past tenure, work has been challenging and productive, and I have thoroughly enjoyed working in your team . Thank you for the opportunities for professional and personal development that you have provided me during the last **months.
Please accept my letter of resignation.

Sincerely,
Employee name
+Mobile number

SIGNAL ENCODING

We can represent bits as digital electrical signals in many ways. Data bits can be coded into following two types of codes :

(a)               Non Return to Zero (NRZ Codes).

(b)               Return to Zero (RZ Codes)

NRZ Codes

In this type of codes, the signal level remains constant during a bit duration. There are 3 types of NRZ codes.

NRZ-L Coding

Bit is represented as a voltage level which remains constant during the bit duration.

NRZ-M Coding

A transition in the beginning of a bit interval whenever there is a 'Mark.

NRZ-S Coding

A transition in the beginning of a bit interval whenever there is a 'Space'. Let us see the following bit stream 10100110 into three different types of NRZ codes 

RZ Codes:

Following are the RZ Codes

(a)        Manchester Coding

(b)        Biphase-M Coding

(c)         Biphase-S Coding

(d)        Differential Manchester Coding.

Manchester Coding

There '1' is represented as the clock pulse itself and '0' as inverted clock pulse. It is widely used in local area networks. Fig.21 shows representation of '1' and '0'.

Bi-phase M Coding

  There is always a transition in the beginning of a bit interval and binary '1' is having additional transition in the middle of the bit interval.

Bi-phase S Coding

There is a transition at the beginning of a bit interval and binary '0' is having additional transition in the middle of the bit interval.

Differential Manchester Coding

There is always a transition in the middle of the bit interval and Binary '0' has additional transition in the beginning of the bit interval. Let us see Fig.22 in which bit sequence 10100110 has been shown in different RZ codes. 

TRANSMISSION CODES in Telecom

All data communication codes are based on the binary system (1s and 0s). A message can be encoded into a meaningful string of 1s and 0s that can be transmitted along a data line and decoded by a receiver. The string of 1s and 0s is meaningful because it is defined by a code that is known to both the source and the receiver. Code is limited by the number of bits (binary digits) it contains, e.g. one-bit code means that we can have 2 characters so that we can encode the letter A by '0' and B by '1'. Similarly, a 2 bit code will enable us to handle 4 characters. Thus, a n-bit code enables us to handle 2ⁿ characters. 

Some commonly used codes are :

1.             Baudot code

2.             ASCII code

3.             BCDIC code

4.             EBCDIC Code

ASCII Code (American Standard Code for Information Interchange)

It is an eight-bit code which consists of seven information bits and one bit for parity checking. This is most widely used data code. Seven information bits gives us 128 combinations, which allows us to encode a full keyboard of the computer.

-          52 alphabets (capital and small).

-          0-9 (10 numbers).

-          Punctuation marks

-          Additional graphic and control characters.

BCDIC (Binary Code Decimal Interchange Code)

It is a six-bit code that is used as an internal code by some computers. With 6 information bits, we can have 2⁶ = 64 possible code combinations. For data transmission, code is implemented as 7-bit code containing 6 information bits and one parity bit.

EBCDIC (Extended Binary Coded Decimal Interchange Code)

It is a 8-bit code in which all the 8-bits are used for information (unlike ASCII), giving 256 possible code combinations. EBCDIC is used as an internal machine code in some of the computers. 

TEMS CELLPLANNER UNIVERSAL

TEMS CellPlanner Universal is Ericsson´s tool for mobile radio network planning. It is a highly graphical, easy-to-use, PC-based tool for design, realization, and optimization of mobile radio networks. TEMS CellPlanner Universal helps the user to roll out and expand mobile radio networks, and optimize radio network regarding service availability and service quality. It assists the user in a number of complex tasks, including network dimensioning, traffic planning, site configuration, and frequency planning. TEMS CellPlanner Universal is the key to successfully competing in the market place.

TEMS CellPlanner Universal provides support for WCDMA, GSM 850, GSM 900, GSM 1800, GSM 1900, iDEN, CDMA, CDMA2000 1xRTT, TDMA/AMPS, NMT 450, NMT 900, TACS, and E-TACS. TEMS CellPlanner Universal also provides support for GPRS and EGPRS (EDGE), implemented in GSM system

The modular platform makes it possible to customize TEMS CellPlanner Universal to meet the needs of every customer. TEMS CellPlanner Universal can be used in all phases of a radio networks life cycle, from early planning to the most complex optimization. The combination of the modular platform and a modern programming language also make it possible to add new functionality in a fast and easy way. In addition, open interfaces enable connection to external data sources for easy exchange of data.

TEMS CellPlanner Universal incorporates the following major features:

·         User-friendly, intuitive menu structure and guided work flows.

·         TEMS CellPlanner Universal uses an Ericsson-developed GIS Engine specially developed to fit the needs of a demanding RF planning tool. TEMS CellPlanner Universal can read several map data formats natively, and it also handles multiple resolutions.

·         Propagation prediction modeling and calculation of signal coverage and interference.

·         Allows real network deployment scenarios such as layered network architectures, distributed antennas, repeaters, and macro-/micro cells. It supports both Baseband and Synthesized Frequency hopping with MAIO management.

·         Efficient and sophisticated radio propagation in urban and rural environments including automatic model tuning

·         Direct import of TEMS™ logfiles to tune propagation models or analyze network performance

·         True Multi-technology support.

·         TEMS CellPlanner Universal 5.0 was designed to be a multi standard/multi-technology RF planning tool. All technologies can co-exist in the same session. Each technology follows the same flow, making it easier for the user to understand the tool.

·         Generic import interface

TRANSMISSION in telecommunication

For understanding the data communication following terminology is discussed: -

·         Communication lines

The medium that carries the message in a data communication system, example of  A 2W telephone line.

  Communication Channel

A channel is defined as a means of one way transmission.

It can carry information in either direction but in only one direction at a time, e.g. A hose pipe. It can carry water in either direction, but the direction of flow depends on which end of pipe is connected to the water tap.

 Simplex Transmission

1.     Message always flows in one direction only.

2.     An input Terminal can only receive and never transmit.

3.     An O/P Terminal can only transmit and never receive.

Half Duplex Transmission

-         A half duplex channel can transmit and receive but not simultaneously.

-         Transmission flow must halt each time and direction is to be reversed.

-         This halt is called the turn-around time and is typically 8 to 10 ms in the case of leased circuits and 50-500 ms in case of 2W telephone line through Public Switched Telephone Network (PSTN). 

Full-duplex Transmission

It is both way communications. If we set up a communication line with two channels, we have the capability of sending information in both directions at the same time. This is called full duplex transmission system. 

TYPES OF HDLC FRAMES

There are three types of HDLC frames :

·         Information transfer frame (I-Frame)

·         Supervisory frame (S-Frame)

·         Unnumbered frame (U-Frame)

Information Transfer Frame (I-FRAME)

I-Frame is used for transporting user data. It also carries acknowledgement of the received frames. The control field of the I-Frame is as shown in Fig.7. The first bit is 0 which identifies the frame as an I-Frame. The next three bits are the sequence number N(S) of the frame.

The fifth is Poll/Final (P/F) bit. Its use is explained later.

The last three bits are the sequence number N(R) of the acknowledgement (RR) which is piggy backed on the I-Frame. 

Supervisory frame (S-FRAME)

S-Frame does not have data field (Fig.3b) and is used to carry only acknowledgements, requests for retransmission, etc. It is identified by the first two bits of the control field (Fig. 8). These two bits are 10 in an S-Frame. The next two bits (SS) are used to indicate four supervisory states. Receive Ready (RR), Receive Not Ready (RNR), Reject (REJ) and Selective Reject (SREJ).

The fifth bit is Poll/Final bit. The last three bits are the sequence number associated with the supervisory states RR, RNR, REJ and SREJ indicated in the SS-Bits of the control field. Note that an acknowledgement (RR) can be sent either on a supervisory frame or piggybacked on an I-Frame as mentioned earlier. On the other hand RNR, REJ and SREJ are sent only through a supervisory frame.

Unnumbered Frame (U-Frame)

The U-Frames do not have data field as S-Frames. They are used for link establishment, termination, mode setting and other control functions. Controls field of an unnumbered frame is shown in Fig.9.

The first two bits of the control field are 11 which identify an unnumbered frame. The fifth bit is Poll/Final bit. The rest five bits are called modifier bits. They specify the control function.