Heterogeneous Networks: Key HetNet Technologies and Deployment Scenarios. Heterogeneous Computer Network Semantics of “Heterogeneous Computer Networks” in Telecommunications
As the demand for mobile data exceeds all expectations, a heterogeneous network architecture with multiple frequency bands, different radio access technologies, and base stations with different coverage areas is the only solution to keep operators moving forward.
In the field of telecommunications, alarming statistics are widely known regarding the demand for data transmission, especially in places where people are most congested. High demand is forcing operators to increase the density of base stations (BS) and increase spectral efficiency through MIMO (Eng. Multiple Input Multiple Output) and other LTE technologies. However, sooner or later, the possibility of deploying new base stations will reach the limit due to frequency overuse and high cost, and their installation will become impractical in large cities. Therefore, it becomes necessary to install Wi-Fi access points, small base stations and other elements to "fill in the gaps" that together form a heterogeneous network (HetNet).
Key technologiesHetNet
One of the key tasks is the "seamless" (invisible) integration of small base stations in the network: their installation can Negative influence on key performance indicators, such as a drop in transmission rate as a result of interference from macro and micro BS.
To unload the macro BS, it will take quite a large number of small base stations installed in crowded places, however, the requirements for their deployment and costs can be low due to the summing up of the transmission already available on the site and built-in power supplies.
1. Precise definition of places where small base stations are needed.
Small BS are effective for unloading macro BS when they are installed in crowded places. Operators can create network traffic maps by collecting information about the location of micro and macro BS, the amount of circulating traffic and the location of user terminals (UE) in the network at the moment. Given the size of the micro BS coverage area, the recommended accuracy for the traffic map is 50 × 50 meters. Operators can evaluate the performance of a micro BS by comparing pre-deployment and post-deployment traffic maps to help make further optimizations in the future.
2. Integration of micro BS.
Purchasing a whole new site with lots of equipment becomes expensive and inefficient, necessitating the deployment of small BSs on poles and walls. To achieve this, transmission elements, power supplies and surge protectors can be integrated with everything else in a convenient BS form factor (spherical or rectangular), not exceeding 8 kg (so that one person can easily install it).
3. Flexible transmission.
Transmission is a serious issue when deploying micro BS. For its summing up, both fixed and wireless methods can be used.
Fiber is the primary means for BSs with fixed transmission routing via point-to-point (P2P) or passive optical network (xPON) connections.
The wireless connection of small base stations is more flexible, but less reliable. Typical solutions in this issue are the use of 60 GHz microwaves, LTE TDD, eBand microwaves, or Wi-Fi connectivity, each of which has its own advantages.
Unlicensed 60 GHz proves to be cost effective if short haul, high throughput transmission is expected; while the use of LTE TDD will be effective in non-line-of-sight environments, and Wi-Fi will be useful in providing low-cost services.
4. Exploit opportunitiesSON (self-organized networks).
To meet mobile broadband demand over the next five years, the number of small BSs must consistently exceed the number of macro BSs. Easy deployment and Maintenance, which take place in SON, play an important role in reducing operating costs in the long term.
A self-organizing micro BS can automatically scan the conditions of its radio environment, whereby it automatically plans and configures parameters such as frequency, scrambling code, and transmission powers. A traditional BS cannot do this, which is why a micro BS with SON functions saves 15% of man-hours for network planning.
Moreover, such a micro BS can automatically detect changes in the radio environment; when another micro BS is deployed next to it, it can automatically optimize the network parameters. For traditional networks, network optimization is a critical part of network maintenance. And when it becomes automatic, labor costs are reduced by 10 to 30%.
5. Coordination of macro-micro BS
One of the key benefits of the HetNet architecture is that it allows for incremental and flexible network capacity growth based on demand rather than prediction. Hotspots that are infrequent in the area require only a few micro BSs, and they can use the same frequencies in the same way that macro BSs do. However, coordination is needed to reduce interference between them. When the amount of traffic in a Hotspot increases and enough micro BSs are deployed, engineers can flexibly allocate carriers among the micro BSs to maximize capacity.
With deployed micro BSs, their coordination with macro BSs increases the overall throughput honeycombs by 80 - 130%.
Deployment scenarios
1. Indoor
Indoor pavement is classified by division (multiple or not) and according to the size of the pavement (small, medium or large). A typical location for small to medium coverage multi-access BSs would be a residential building, supermarkets, subways and medium-sized conference rooms, and other areas with low ceilings, moving users and high demands containers. This type includes LTE pico cells and the use of Wi-Fi.
Large multi-user indoor hotspots include large office buildings, hotels, and other places where high density users with high demand. However, both of these requirements, both capacity and demand, must be considered together, taking into account the availability of elevators and a large number of floors (vertically, macro BS coverage is often poor).
2. Outdoor
Outdoor coverage falls into three categories - small, independent Hotspots ("HotDots"), outdoor Hotspots ("HotLines"), and large zonal Hotspots ("HotZones").
In "HotDot" (cafe) demand is high but coverage is quite low and users are mostly on site. In "HotLine" subscriber density and demand is high and coverage is comparable to a city street, with "HotLine" actively interacting with all services and businesses on that street, which should be taken into account when deploying "HotZone" generally refers to large areas and others public places where user density and demand are high, but only under certain circumstances, which are often quite predictable.
The outdoor coverage can use LTE microcells, and the small cells of the indoor coverage should mainly complement the outdoor coverage, being used in conjunction with it.
Conclusion
The mobile networks of the future will need significant capacity and user experience, and this will be achieved with HetNet. Micro BS should be placed in places of mass congestion of people and a large amount of traffic to unload macro BS. Proper coordination is required: macro and micro BS should have minimal influence on each other. Any micro BS must integrate batteries, feeder and surge protection to minimize space requirements and deployment costs. An optimized next-generation indoor coverage should provide for flexible and versatile base station placement, incremental capacity expansion, and remote service capabilities. Some deployment scenarios are already in place and operators must now tailor them to their own needs.
Prepared by: Romanshenkov N.O.
- A heterogeneous computer network is a computer network that connects personal computers and other devices with different operating systems or data transfer protocols. For example, a local area network (LAN) that connects computers running Microsoft Windows, Linux, and MacOS operating systems is heterogeneous.
The term "heterogeneous networks" is also used in wireless computer networks, where various technologies are used to connect. For example, a computer network that provides access via a wireless LAN and is capable of providing access by switching to a cellular connection is also referred to as a heterogeneous network.
Related concepts
Internetworking is a way of connecting a computer network to other networks using gateways that provide a common way to route information packets between networks. The resulting system of interconnected networks is called a composite network, or simply an internet.
Media access control (or medium access control, MAC) is a sublayer of the data link (second) layer of the OSI model, according to IEEE 802 standards.
local area network (LAN, the local network; English Local Area Network, LAN) is a computer network that usually covers a relatively small area or a small group of buildings (home, office, company, institute).
Computer network (computer network) - a system that provides data exchange between computing devices (computers, servers, routers and other equipment). Various media can be used to transfer information.
References in literature
Let's try to figure out what fundamentally new informatization gives. First of all, informatization is the application computer technology. AT state of the art this means the widespread use of geographically distributed heterogeneous computer networks and systems. It is necessary to immediately distinguish two fundamentally different levels:
Related concepts (continued)
Overlay network (from the English. Overlay Network) - a general case of a logical network created on top of another network. Overlay network nodes can be connected either by a physical connection or by a logical one, for which one or more corresponding routes from physical connections exist in the main network. Examples of overlays are VPNs and peer-to-peer networks that operate on the basis of the Internet and are “add-ons” to classic network protocols, providing ample opportunities ...
Smartstation (from the English. Smartstation - "smart station") is a class of electronic multifunctional devices that simultaneously perform the functions of an L2 / L3 router, wireless wifi access point, VoIP gateway, PBX, DECT base station, NAS network storage, print server and other network devices.
Industrial network - a data transmission network that connects various sensors, actuators, industrial controllers and is used in industrial automation. The term is used primarily in automated systems management technological processes(APCS). Described by the IEC 61158 standard. Devices use the network to...
Wireless ad-hoc network (wireless dynamic network, wireless ad hoc network) is a decentralized wireless network that does not have a permanent structure. Client devices are connected on the fly, forming a network. Each node on the network attempts to forward data destined for other nodes. In this case, the determination of which node to send data to is made dynamically, based on the connectivity of the network. This is different from wired networks and managed wireless networks, where...
Interface (from English interface) - a common boundary between two functional objects, the requirements for which are determined by the standard; a set of means, methods and rules of interaction (management, control, etc.) between the elements of the system.
Switching in a computer network is the process of connecting subscribers of such a network through transit nodes. Computers, segments of local networks, fax machines or telephone interlocutors can act as subscribers. As a rule, in public networks it is impossible to provide each pair of subscribers with their own physical communication line, which they could exclusively “own” and use at any time. Therefore, the network always uses some method of switching subscribers, which ensures the separation of available ...
Global Area Network, WAN (Eng. Wide Area Network, WAN) - a computer network covering large areas and including a large number of nodes.
Hierarchical internetworking model is a three-level model of organization of a company's network, first proposed by Cisco Systems engineers. Divides the company's network into three levels of hierarchy: network core (eng. core layer), distribution level (eng. distribution layer), access level (eng. access layer).
Network Functions Virtualization (NFV) is a network architecture concept that proposes using virtualization technologies to virtualize entire classes of network node functions in the form of composite elements that can be connected together or linked in a chain to create telecommunication services (services) . The concept of network function virtualization was proposed in 2012 by the European Telecommunications Standards Institute (ETSI).
Wireless personal area networks (WPAN) - networks whose standard has been developed working group IEEE 802.15.
Computer telephony (CTI, eng. Computer Telephony Integration) - technologies that ensure the interaction of computers and traditional telephone networks. Computer telephony allows you to combine voice transmission with digital data transmission, as well as provide call tracking and control for any scenario (voice, Email, web interface, fax, etc.). Computer telephony is used, in particular, in the creation of call centers and instead of office automatic telephone exchanges. Exist...
A communication network is a system of physical communication channels and switching equipment that implements one or another low-level data transfer protocol. There are wired, wireless (using radio waves) and fiber optic communication channels. According to the type of transmitted signal, digital and analog networks are distinguished. The purpose of communication networks is to transmit data with a minimum number of errors and distortions. An information network can be built on the basis of a communication network, for example ...
Software-defined network or software-defined networking (English software-defined networking, SDN) is a data network in which the network control level is separated from data transmission devices and is implemented in software. One form of network virtualization.
Heterogeneous computing systems are electronic systems that use different types computing blocks. The computing units of such a system may be a general purpose processor (GPP), a processor special purpose(e.g. digital signal processor (DSP) or GPU(GPU)), co-processor, acceleration logic (application-specific integrated circuit (ASIC) or field programmable gate array (FPGA)).
Intelligent network (English Intelligent Network, IN) - a method of organizing a communication network focused on the introduction of services into the network and their management. The concept behind the smart grid defines the hardware and software architecture that allows data to be exchanged between the switching system and the network during communication between nodes. The principle of building an intelligent network was introduced by the International Telecommunication Union.
The master device (eng. Master - lit. "master") is the main device on the network, which can independently request data from slave devices, or send broadcast messages.
Terminal system - organization of network operation scheme information system, allowing you to optimize financial costs to build a powerful, flexible and reliable information system (IS).
Software-defined storage network (also ... storage system, ... storage environment; English software-defined storage, SDS) - a software solution that provides the creation of a storage network on non-specialized mass-class equipment, usually a group of x86-64 architecture server nodes under management of general purpose operating systems (Linux, Windows, FreeBSD). The main distinguishing feature is the virtualization of the storage function, separating the hardware from the software, which...
Virtualization is the provision of a set of computing resources or their logical combination, abstracted from the hardware implementation, and at the same time providing logical isolation from each other of computing processes running on the same physical resource.
Wireless LAN (English Wireless Local Area Network; Wireless LAN; WLAN) - a local area network built on the basis of wireless technologies.
Wireless computer network - a computer network based on a wireless (without the use of cable wiring) principle, fully compliant with the standards for conventional wired networks (for example, Ethernet). Microwave radio waves can act as information carriers in such networks.
A switch without an operating system (eng. Bare-metal switch, BMS, literally - “switch on bare iron”) is a type of network switches that come without a built-in software, but with the ONIE Software Boot Environment for installing compatible Linux-based network operating systems. This allows consumers to replace the network operating system and avoid being tied to a hardware vendor, and also fits into the trend of building software-defined networking...
APKSH "Continent" (hardware and software encryption complex "Continent") - a hardware and software complex that allows you to provide protection information networks organizations from intrusion from data transmission networks (Internet), confidentiality in the transmission of information over open communication channels (VPN), organize secure access for VPN users to public network resources, as well as secure interaction between networks of various organizations.
The radio network controller or RNC (r-n-si, English Radio Network Controller - radio network controller) is a control element in the UMTS radio access network (UTRAN), which controls the Node B base stations connected to it. The RNC performs radio resource management functions, some functions according to mobility management, as well as RNC encrypts or decrypts user data transmitted or received from mobile phone user. The RNC connects to the circuit-switched core network...
Router (prof. slang. Rýter transliteration from English router /ˈɹu:tə(ɹ)/ or /ˈɹaʊtəɹ/, /ˈɹaʊtɚ/) is a specialized computer that forwards packets between different network segments based on rules and routing tables. A router can link heterogeneous networks of different architectures. Information about the network topology and certain rules set by the administrator are used to make decisions about forwarding packets.
Cryptographic gateway (cryptographic gateway, vpn gateway, cryptorouter) - a hardware and software complex for cryptographic protection of data, voice, video traffic based on packet encryption using the IPsec AH and / or IPsec ESP protocols when a connection is established that meets the requirements for cryptographic information protection (CIPF) ) of the Federal Security Service of Russia and provides the basic functionality of a modern VPN device.
System software is a set of programs that provide control of computer system components, such as a processor, RAM, input-output devices, network equipment, acting as an “interlayer interface”, on one side of which is the equipment, and on the other - user applications.
Cluster - a group of computers united by high-speed communication channels, representing a single hardware resource from the user's point of view.
Computer network management - the implementation of many functions necessary for the control, planning, allocation, implementation, coordination and monitoring of computer network resources.
Mesh topology - a network topology of a computer network, built on the principle of cells, in which network workstations are connected to each other and are able to assume the role of a switch for other participants. This network organization is rather complicated to set up, however, with such a topology, high fault tolerance is realized. As a rule, nodes are connected on a one-to-one basis. Thus, a large number of connections provides a wide choice of traffic route...
A network element is a managed logical entity that connects one or more physical devices. This approach allows you to manage distributed devices using one control system as a whole.
A point-to-point network, a point-to-point connection, is the simplest type of computer network in which two computers are directly connected to each other through communication equipment. The advantage of this type of connection is simplicity and low cost, the disadvantage is that no more than two computers can be connected in this way, in contrast to such data transmission methods as broadcasting and point-to-multipoint.
Storage Area Network (SAN) is an architectural solution for connecting external storage devices such as disk arrays, tape libraries, optical drives to servers in such a way that the operating system recognizes the connected resources as local.
A transport communication network (backhaul) is a collection of all resources that perform transport functions in telecommunication networks. It includes not only transmission systems, but also the means of control, operational switching, redundancy, and control related to them. In cellular communication transport network includes the network section between the operator's backbone network and the base station.
Star - the basic topology of a computer network in which all computers in the network are connected to a central node (usually a switch), forming a physical network segment. Such a network segment can function both separately and as part of a complex network topology (usually a "tree"). The entire exchange of information goes exclusively through the central computer, which in this way has a very large load, so it cannot do anything other than the network. As a rule, it is the central ...
Failover cluster (English High-Availability cluster, HA cluster - high availability cluster) - a cluster (a group of servers) designed in accordance with high availability techniques and guaranteeing minimal downtime due to hardware redundancy. Without clustering, a server failure causes the applications or network services it supports to be unavailable until it is back up. Failover Clustering fixes this situation...
Information technologies (IT, also - information and communication technologies) - processes, methods for searching, collecting, storing, processing, providing, distributing information and methods for implementing such processes and methods (Federal Law No. 149-FZ); techniques, methods and methods of using funds computer science when performing the functions of collecting, storing, processing, transmitting and using data (GOST 34.003-90); resources needed to collect, process, store and disseminate information (ISO/IEC...
Videoconferencing (from the English videoconference) is an area of information technology that simultaneously provides two-way transmission, processing, transformation and presentation of interactive information at a distance in real time using computer hardware and software.
A wireless access point (English Wireless Access Point, WAP) is a wireless base station designed to provide wireless access to an existing network (wireless or wired) or create a new wireless network.
Network gateway (eng. Gateway) - a hardware router or software for interfacing computer networks using different protocols (for example, local and global).
In the field of information and computer systems a configuration is understood as a certain set of components, based on their purpose, number and main characteristics. Often, configuration means selecting hardware, software, firmware, and supporting documentation. The configuration affects the operation and performance of the computer. Also in operating system you can manually set the driver settings.
Network heterogeneity- heterogeneity of communication and hardware configuration, as well as software in structured networks.
Methods:
· Encapsulation
It is used in cases where: - it is necessary to organize data exchange between two networks built using the same technology, using different physical. Wednesdays; -when 2 networks are not connected directly, but through intermediate networks using different technologies.
Principles: 1. Transport packages protocols to be sent through the transit network are encapsulated; 2. After passing through the transit network, the reverse process of decapsulation and forwarding to the addressee takes place. Advantage: fast and easy to implement method
Flaw: does not provide interaction with the nodes of the transit network.
· Broadcast - harmonization of 2 protocols by converting the format of messages coming from one network to the format of another network. Broadcasting can be done by bridges, switches, routers, and gateways. Flaw: laborious, with t.z. processing power of methods, which can reduce the speed of data transfer over the network.
· Multiplexing
A method when nodes simultaneously install and configure the simultaneous operation of several protocol stacks at once, which allows them to process messages from nodes of heterogeneous subnets.
Multiplex. protocols- Software that performs the task of determining the use of the received protocol stack message. Advantages : - simpler method to implement than translation; - overcoming network bottlenecks; no queues to a single gateway device. Flaws: administering and monitoring network performance becomes more complicated; redundancy requires additional resources to the workstation.
21. Network layer routing. Routing table. routing algorithms. The concept of metrics.
21. Packet routing. Routing table. routing algorithms. The concept of metrics.
Routing - a mechanism that allows in a structured heterogeneous network to deliver packets from one node to another. Routing can be done:
· on the canal level (through bridges and switches).
Restrictions interactions that occur at the channel level:
1. At the link layer, d.b. one system physical addressing
2. Topology should not contain loops, i.e. between the sender and the recipient is always d.b. the only route.
· On the network level (using routers).
A forwarding route is a sequence of routers connecting transit networks.
Route information in the table may contain:
Information about all existing and available routes
Information only about the nearest routes responsible for further data transfer to the destination node.
Table entry. routing contains fields: address of the destination network or host, address next. march-ra, auxiliary fields. Ways to fill in the tables: manually by the administrator or through special. routing information collection protocols. On a network, each host maintains its own routing table.
The choice of a route from the route table is based on a specific routing algorithm. Algorithms : static and dynamic (adaptive).
One- and multi-path algorithms (usually one route is the main one, and the rest are backup).
Single-level and hierarchical
single level- all routers are equal among themselves.
Hierarchical- are used in networks divided into subnets with their own routing within each level.
Metrics- indicators used by algorithms to determine the optimal route.
Route length measured in number of hops
Time delay - the time it takes for a packet to travel from source to destination
communication cost
Reliability indicator (ratio of the number of errors to the number of transmitted bits)
・Bandwidth
Physical distance between nodes
22. Protocols for collecting routing information RIP and OSPF.
- Dignities and clothes of Orthodox priests and monasticism
- Healers and fortune tellers - why do people go to them?
- During confession. Preparation for confession. List of sins for confession. How to dress for confession
- Praise of the Most Holy Theotokos Praise of the Mother of God with an akathist what they pray for