To install click the Add extension button. That's it.

The source code for the WIKI 2 extension is being checked by specialists of the Mozilla Foundation, Google, and Apple. You could also do it yourself at any point in time.

4,5
Kelly Slayton
Congratulations on this excellent venture… what a great idea!
Alexander Grigorievskiy
I use WIKI 2 every day and almost forgot how the original Wikipedia looks like.
Live Statistics
English Articles
Improved in 24 Hours
Added in 24 Hours
What we do. Every page goes through several hundred of perfecting techniques; in live mode. Quite the same Wikipedia. Just better.
.
Leo
Newton
Brights
Milds

From Wikipedia, the free encyclopedia

There are two types of radio network currently in use around the world: the one-to-many (simplex communication) broadcast network commonly used for public information and mass-media entertainment, and the two-way radio (duplex communication) type used more commonly for public safety and public services such as police, fire, taxicabs, and delivery services. Cell phones are able to send and receive simultaneously by using two different frequencies at the same time. Many of the same components and much of the same basic technology applies to all three.

The two-way type of radio network shares many of the same technologies and components as the broadcast-type radio network but is generally set up with fixed broadcast points (transmitters) with co-located receivers and mobile receivers/transmitters or transceivers. In this way both the fixed and mobile radio units can communicate with each other over broad geographic regions ranging in size from small single cities to entire states/provinces or countries. There are many ways in which multiple fixed transmit/receive sites can be interconnected to achieve the range of coverage required by the jurisdiction or authority implementing the system: conventional wireless links in numerous frequency bands, fibre-optic links, or microwave links. In all of these cases the signals are typically backhauled to a central switch of some type where the radio message is processed and resent (repeated) to all transmitter sites where it is required to be heard.

In contemporary two-way radio systems a concept called trunking is commonly used to achieve better efficiency of radio spectrum use and provide very wide-ranging coverage with no switching of channels required by the mobile radio user as it roams throughout the system coverage. Trunking of two-way radio is identical to the concept used for cellular phone systems where each fixed and mobile radio is specifically identified to the system controller and its operation is switched by the controller.

YouTube Encyclopedic

  • 1/5
    Views:
    24 576
    8 505
    3 981
    4 349
    1 464
  • ✪ 3.2 - LTE 4G RAN ARCHITECTURE - eUMTS - INTRODUCTION
  • ✪ HIGH FREQUENCY RADIO NETWORK- 12-30-2018
  • ✪ Brad Johnson and Adronis on One Radio Network (12.03.19)
  • ✪ Maezer Semay TV and Radio Network: ቃለ መጠይቕ ምስ ፓስተር ኣሮን ተስፋይ 1ይ ክፋል
  • ✪ HIGH FREQUENCY RADIO NETWORK

Transcription

In previous Generations, the base stations were controlled by a central device. In 2G, it was the base station controller, and in 3G it was the RNC. These controllers were responsible - For setting up the radio links to wireless devices via the base stations, For controlling the connections while in use, For ensuring QoS and for handing over a connection to another base station when required. In LTE, this concept was abandoned, as it required significant resources, because the task was concentrated in few network nodes. Most applications on the device only transmit and receive information in bursts with long timeouts in between. During these times of inactivity, the air interface connection to the mobile device has to be changed to use the available bandwidth efficiently and to reduce the power consumption of mobile devices. So The packet-switched connections generate a lot of signaling load because of the frequent switching of the air interface state. So these management task were distributed, to speed up the connection setup time and reduce the time required for handover, which is very crucial for real time services. Thus making the LTE access network a simple flat network of interconnected Base Stations without a centralised controller. Hello everyone, Welcome back to the world of LTE today we will discuss the Radio Access Network of LTE which is also called evolved UMTS Terresterial Radio Access Network or eUTRAN. The most complex node in the LTE network is the base station, referred to as eNode-B. It is derived from the name which was originally given to the UMTS base station (Node-B) with an ‘e’ referring to ‘evolved’. eNode-Bs consist of 2 major elements: • RRU or the Remote Radio Unit consists of the antennas, It is also called as remote radio head, which are the most visible parts of a mobile network. They are also responsible for Modulation and Demodulation of all signals transmitted or received on the air interface; •The BBU or Base Band Unit consists of digital modules that process all signals transmitted and received on the air interface and acts as an interface to the core network over a high-speed backhaul connection. Now,In LTE base stations are autonomous units. Most functions of the RNC were integrated into the eNodeB. Hence, the eNode-B is not only responsible for the air interface but also for Radio Resource Management that includes - Radio Bearer Control - Radio Admission Control - Connection Mobility Control - Scheduling i.e Dynamic allocation of resources to UEs in both uplink and downlink It is also responsible for, - IP header compression and encryption of user data stream - Selection of an MME at UE attachment when no routing to an MME can be determined from the information provided by the UE - Routing of User Plane data towards Serving Gateway - Scheduling and transmission of paging messages (originated from the MME) - Scheduling and transmission of broadcast information (originated from the MME or O&M) - Measurement and reporting configuration for mobility and scheduling Now, The interface between the base station and the core network is referred to as the S1 interface. It is usually carried either over a high-speed copper or fiber cable, or alternatively over a high-speed microwave link. The S1 interface is split into two logical parts, which are both transported over the same physical connection- User data is transported over the S1 User Plane part of the interface. IP packets of a user are tunneled through an IP link in a manner similar to that already described for GPRS to enable seamless handovers between different LTE base stations and UMTS or GPRS/EDGE. In fact, the GPRS Tunneling Protocol (GTP) is reused for this purpose. Only the destination IP address on layer 3 (the tunneling IP layer) is changed, while the user’s IP address remains the same. The S1 Control Plane (S1-CP) protocol, as defined in 3GPP (TS 36.413, [7]) is required for two purposes: Firstly, the eNode-B uses it to interact with the core network for its own purposes, that is, to make itself known to the network, to send status and connection keep-alive information and for receiving configuration information from the core network. Secondly, the S1-CP interface is used for transferring signaling messages that concern the users of the system. For example, when a device wants to communicate using the LTE network, an individual logical connection has to be established and the core network is responsible for authentication, for supplying keys for encrypting data on the air interface and for the establishment of a tunnel for the user’s data between the eNode-B and the core network. Once the user’s data tunnel is in place, the S1-CP protocol is used to maintain the connection, to organize a handover of the connection to another LTE, UMTS or GSM base station as required. In S1-CP protocol stack, Instead of the commonly known TCP and UDP protocols on layer 4, the Telecom-specific Stream Control Transmission Protocol (SCTP) is used as defined in RFC 4960. It ensures that a large number of independent signaling connections can be established simultaneously with in-sequence transport, congestion management and flow control. Now, As mentioned earlier, Unlike the previous generation technologies, LTE integrates the radio controller function into the eNodeB. This allows tight interaction between the different protocol layers of the radio access network, thus reducing latency and improving efficiency. Such distributed control eliminates the need for a high-availability, processing-intensive controller, which in turn has the potential to reduce costs and avoid ‘single points of failure’. One consequence of the lack of a centralized controller node is that, as the UE moves, the network must transfer all information related to a UE, i.e. the UE context, together with any buffered data, from one eNodeB to another. So to avoid data loss during handover, X2 interface was introduced. In LTE, base stations can communicate directly with each other over the X2 interface for two purposes: First, handovers are now controlled by the base stations themselves. If the target cell is known and reachable over the X2 interface, the cells communicate directly with each other. Otherwise, the S1 interface and a core network are employed to perform the handover. The second use of the X2 interface is for interference coordination. As in UMTS, neighboring LTE base stations use the same carrier frequency, there are areas in the network where mobile devices can receive the signals of several base stations. If the signals of two or more base stations have a similar strength, the signals of the base stations that the mobile device does not communicate with at that moment, are perceived as noise and the resulting throughput suffers significantly. As mobile devices can report the noise level at their current location and the perceived source to their serving base station, the X2 interface can then be used by that base station to contact the neighboring base station and agree on methods to mitigate or reduce the problem. So friends, in this video we have seen how limitations of previous generations were mitigated by Decentralizing the Radio access network in LTE. In our next video we will be discussing about the Evolved Packet Core. Happy Learning.

Contents

Broadcasting networks

The broadcast type of radio network is a network system which distributes programming to multiple stations simultaneously, or slightly delayed, for the purpose of extending total coverage beyond the limits of a single broadcast signal. The resulting expanded audience for radio programming or information essentially applies the benefits of mass-production to the broadcasting enterprise. A radio network has two sales departments, one to package and sell programs to radio stations, and one to sell the audience of those programs to advertisers.

Most radio networks also produce much of their programming. Originally, radio networks owned some or all of the stations that broadcast the network's radio format programming. Presently however, there are many networks that do not own any stations and only produce and/or distribute programming. Similarly station ownership does not always indicate network affiliation. A company might own stations in several different markets and purchase programming from a variety of networks.

Radio networks rose rapidly with the growth of regular broadcasting of radio to home listeners in the 1920s. This growth took various paths in different places. In Britain the BBC was developed with public funding, in the form of a broadcast receiver license, and a broadcasting monopoly in its early decades. In contrast, in the United States various competing commercial broadcasting networks arose funded by advertising revenue. In that instance, the same corporation that owned or operated the network often manufactured and marketed the listener’s radio.

Major technical challenges to be overcome when distributing programs over long distances are maintaining signal quality and managing the number of switching/relay points in the signal chain. Early on, programs were sent to remote stations (either owned or affiliated) by various methods, including leased telephone lines, pre-recorded gramophone records and audio tape. The world's first all-radio, non-wireline network was claimed to be the Rural Radio Network, a group of six upstate New York FM stations that began operation in June 1948. Terrestrial microwave relay, a technology later introduced to link stations, has been largely supplanted by coaxial cable, fiber, and satellite, which usually offer superior cost-benefit ratios.

Many early radio networks evolved into Television networks.

List of radio networks

Australia

Brazil

Canada

Defunct

China

India

Indonesia

Iran

  • All Iranian radio (many ch.)

Ireland

Japan

South Korea

New Zealand

Almost all radio stations in New Zealand are part of a radio network, and most are network-owned.

Pakistan

Philippines

Poland

  • Public:
    • Polskie Radio
      • Program 1 (Jedynka) - (news, current affairs, easy listening music, focused at listeners aged 40–64) - AM, FM, DAB+ and the internet
      • Program 2 (Dwójka) - (Classical music, drama, comedy, literature) - FM, DAB+ and the internet
      • Program 3 (Trójka) - (Rock, alternative, Middle of the Road, focused at listeners aged 25–49) - FM, DAB+ and the internet
      • Program 4 (Czwórka) - (Dance, R&B, Reggae, Rap, Soul, focused at listeners aged 15–29) - FM, DAB+ and the internet
      • Polskie Radio Dla Zagranicy - (external service in English, Ukrainian, Russian, Belarusian) - AM, FM, DAB+, satellite and the internet
      • Rolskie Radio 24
      • Polskie Radio Rytm
      • Polskie Radio Regionalna
  • Non-commercial:
  • Commercial:
    • Bauer Media Group:
      • RMF FM - hot adult contemporary radio (Target Demographic 18-44) (nationwide)
      • RMF MAXXX
      • RMF Classic
      • Radio GRA
    • Eurozet:
      • Radio Zet - hot adult contemporary radio (Target Demographic 21-49) (nationwide)
      • Radio Zet Gold
      • Radio Zet Chillil
      • Antyradio - rock and metal music (3 local stations)
    • Time company:
      • Radio Eska - contemporary hit radio (Target Demographic 13-29) (40 local stations)
      • Eska Rock - mainly rock music (local station broadcasting in Warsaw)
      • VOX FM - mostly Disco Polo
      • Radio WAWA - only polish music (8 local stations)
    • Joint project of Eurozet and Time:
      • Radio Plus - upbeat oldies from the 1970s to 1990s (Target Demographic 40 and older) (18 local stations)
    • Agora company:
      • TOK FM - rolling news, talk, current affars
      • Zlote Przeboje - mainly oldies music (Target Demographic 30-49) (22 local stations)
      • Rock Radio - rock music (Target Demographic 18-39) (7 local stations)
      • Blue FM - local station in Poznań
    • Other:
      • Muzo.fm - music and news stations
      • Radio Kolor - local station in Warsaw
      • Radio Alfa - local station in Kraków
      • Radio Parada - local station in Łódź
      • Radio Kaszëbë - local station broadcasting in north-central Poland
      • and over 100 other local stations

Turkey

  • All Turkish radio

United Kingdom

United States

International

See also

This page was last edited on 4 March 2019, at 13:33
Basis of this page is in Wikipedia. Text is available under the CC BY-SA 3.0 Unported License. Non-text media are available under their specified licenses. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc. WIKI 2 is an independent company and has no affiliation with Wikimedia Foundation.