5G Spectrum

The growing traffic demand necessitates increasing the amount of spectrum that may be utilised by the

5G systems. High frequency bands in the centimeter wave (cmWave) and millimeter wave (mmWave)

range will be adopted due to their potential for supporting wider channel bandwidths and the consequent

capability to deliver high data rates.

The new spectrum below 6GHz is expected to be allocated for mobile communication at the World Radio

Conference (WRC) 2015, and the band above 6GHz expected to be allocated at WRC 2019, as shown in

Figure.

5G network is a heterogeneous network which enables the cooperation between lower-frequency wide-area coverage network and high-frequency network. The consensus is higher frequency bands are the complementary bands to 5G whereas low frequency bands (<6GHz) are still the primary bands of 5G spectrum.

High frequency also enables unified access and backhaul since the same radio resources is shared. It is expected to use a unified air interface and a hierarchical scheduling for both radio access and backhaul which enables flexible backhauling and low-cost ultra dense networking (UDN).

Future radio access may also employ bands with different levels of access regulation including exclusive licensed, non-exclusive licensed and unlicensed bands. The 5G system treats both the licensed and unlicensed spectrum in a flexible, unified air interface framework.

Wavelength in GSM

There are many different types of electromagnetic waves. These electromagnetic waves can be described by a sinusoidal function, which is characterized by wavelength. Wavelength (l) is the length of one complete oscillation and is measured in meters (m). Frequency and wavelength are related via the speed of propagation, which for radio waves is the speed of light (3 x10^8 m/s or meters per second).

The wavelength of a frequency can be determined by using the following formula:

Wavelength = Speed / Frequency

Thus, for GSM 900 the wavelength is:

Wavelength = 3×10^8 m/s / 900 MHz           

Wavelength = 300,000,000 m/s  / 900,000,000

Wavelength = 0.33 m (or 33 cm)

From this formula it can be determined that the higher the frequency, the shorter the wavelength. Lower frequencies, with longer wavelengths, are better suited to transmission over large distances, because they bounce on the surface of the earth and in the atmosphere. Television and FM radio are examples of applications, which use lower frequencies.

Higher frequencies, with shorter wavelengths, are better suited to transmission over small distances, because they are sensitive to such problems as obstacles in the line of the transmission path. Higher frequencies are suited to small areas of coverage, where the receiver is relatively close to the transmitter.

The frequencies used by mobile systems compromise between the coverage advantages offered by lower frequencies and the closeness-to-the-receiver advantages offered by use of higher frequencies.

Nokia BSC with MML commands:

ZAHP PRINT ALARM HISTORY

ZAHO PRINT ALARMS CURRENTLY ON

ZIGO DISPLAY MML COMMAND LOG

ZWQO SHOW SOFTWARE PACKAGE INFORMATION

ZW7I INTERROGATE LICENCE OR FEATURE INFORMATION

ZEFR RESET SITE/BCF

ZEQS LOCK UNLOCK BTS

ZERS LOCK UNLOCK TRX

ZEQM MODIFY BTS PARAMETERS

ZEAO OUTPUT GSM ADJACENT

ZEUO OUTPUT POWER CONTROL PARAMETERS

ZEHO OUTPUT HANDOVER PARAMETERS

LTE fundamentals

The fundamentals of the LTE Radio interface and get an overview of the evolution of 4G telecommunication. This 19 minutes video is presented by Ericsson expert Sven-Anders Sturesson.

The tutorial gives an overview of the fundamental technology of Long Term Evolution (LTE). You will learn the basics of the LTE radio interface, including multiple input, multiple outputs (MIMO), OFDM, uplink and downlink, SIMO, TDD, FDD, channel coding and GSA.

 

http://www.ericsson.com/ourportfolio/ericsson-academy/online-tutorials/lte_fundamentals_module/player.html



Source: Ericsson

What is Citrix ?

Citrix facilitates real-time access to shared applications over networks and the Internet. Remote access to Citrix-enabled applications can be over DSL, T1, ISDN, or dial-up. Citrix MetaFrame enables multiple users to run shared applications simultaneously. Communication between Citrix clients and servers consists of exchange of user inputs (keyboard/mouse) and screen shots. Citrix MetaFrame runs on Windows NT 4.0 (Terminal Server Edition) and Windows 2000, with Terminal Services installed.

Citrix products include:

• Citrix Access Essentials
• Citrix Access Gateway
• Citrix Access Suite
• Citrix Application Gateway
• Citrix GoToAssist
• Citrix GoToMeeting
• Citrix GoToMyPC
• Citrix NetScaler
• Citrix Password Manager
• Citrix Presentation Server

For technical support and questions regarding Citrix MetaFrame, go to http://support.citrix.com

Multimedia Broadcast Multicast Service, MBMS

Multimedia Broadcast Multicast Service, MBMS

A new service introduced in 3GPP Release 6 specifications is Multimedia Broadcast Multicast Service (MBMS). There are two high level modes of operation in MBMS, as given

 

1.       Broadcast mode, which allows sending audio and video. The already existing Cell Broadcast Service (CBS) is intended for messaging only. The broadcast mode is expected to be a service without charging and there are no specific activation requirements for this mode.

2.        Multicast mode allows sending multimedia data for the end users that are part of a multicast subscription group. End users need to monitor service announcements regarding service availability, and then they can join the currently active service. From the network point of view, the same content can be provided in a point-to-point fashion if there are not enough users to justify the high power transmission. A typical example in 3GPP has been the sport results service where, for example, ice hockey results would be available as well as video clips of the key events in different games of the day. Charging is expected to be applied for the multicast mode.

 

From the radio point of view, MBMS is considered an application independent way to deliver the MBMS User Services, which are intended to deliver to multiple users simultaneously. The MBMS User Services can be classified into three groups as follows

1. Streaming services, where a basic example is audio and video stream;

2. File downloads services;

3. Carousel service, which can be considered as a combination of streaming and file download. In this kind of service, an end user may have an application which is provided data repetitively and updates are then broadcast when there are changes in the content.

 

For MBMS User Services, an operator controls the distribution of the data. Unlike CBS, the end user needs first to join the service and only users that have joined the service can see the content. The charging can then be based on the subscription or based on the keys which enable an end user to access the data. The MBMS content can be created by the operator itself or by a third party and, as such, all the details of what an MBMS service should look like will not be specified by 3GPP, but left for operators and service providers. One possible MBMS high level architecture is shown in Figure, where the IP multicast network refers here to any server providing MBMS content over the Internet.

 

 

 

 

 

Push-to-Talk over Cellular (PoC)

Push-to-talk over cellular (PoC) service is instant in the sense that the voice connection is established by simply pushing a single button and the receiving user hears the speech without even having to answer the call. While ordinary voice is bi-directional, the PoC service is a one directional service. The basic PoC application may hence be described as a walkie-talkie application over the packet switched domain of the cellular network. In addition to the basic voice communication functionality, the PoC application provides the end user with complementary features like, for example:

      ·         Ad hoc and predefined communication groups;

·         Access control so that a user may define who is allowed to make calls to him/her;

·         ‘Do-not-disturb’ in case immediate reception of audio is not desirable.

With ordinary voice calls a bi-directional communication channel is reserved between the end users throughout the duration of the call. In PoC, the channel is only set up to transfer a short speech burst from one to possibly multiple users. Once this speech burst has been transferred, the packet switched communication channel can be released. This difference is highlighted in Figure.

 

 

The speech packets are in the PoC solution carried from the sending mobile station to the server by the OPRS/UMTS network. The server then forwards the packets to the receiving mobile stations. In the case of a one-to-many connection, the server multiplies the packets to all the receiving mobile stations. This is illustrated in Figure  The PoC service is independent of the underlying radio access network.

 

 

 

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