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WO1998004059A1 - Procede et systeme de calcul d'une caracteristique de signal transmis dans un modele d'environnement comportant des elements attenuateurs - Google Patents

Procede et systeme de calcul d'une caracteristique de signal transmis dans un modele d'environnement comportant des elements attenuateurs Download PDF

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Publication number
WO1998004059A1
WO1998004059A1 PCT/US1997/008569 US9708569W WO9804059A1 WO 1998004059 A1 WO1998004059 A1 WO 1998004059A1 US 9708569 W US9708569 W US 9708569W WO 9804059 A1 WO9804059 A1 WO 9804059A1
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WO
WIPO (PCT)
Prior art keywords
attenuator
calculating
signal characteristic
radio frequency
transmitted signal
Prior art date
Application number
PCT/US1997/008569
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English (en)
Inventor
John Douglas Reed
Shu-Shaw Wang
Original Assignee
Motorola Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Motorola Inc. filed Critical Motorola Inc.
Publication of WO1998004059A1 publication Critical patent/WO1998004059A1/fr

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B17/00—Monitoring; Testing
    • H04B17/30—Monitoring; Testing of propagation channels
    • H04B17/391—Modelling the propagation channel
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B17/00—Monitoring; Testing
    • H04B17/30—Monitoring; Testing of propagation channels
    • H04B17/373—Predicting channel quality or other radio frequency [RF] parameters

Definitions

  • the present invention is related in general to calculating radio signal propagation, and more particularly to an improved method and system for calculating a transmitted signal characteristic in an environmental model using raytracing techniques.
  • base station antennas In a wireless communication system, such as a cellular telephone system or personal communications services (PCS) system, base station antennas should be located so that suitable radio signals are available everywhere in the service area.
  • PCS personal communications services
  • Another problem in locating base station antennas is obtaining adequate signal coverage in areas having various objects that impede radio frequency signal propagation.
  • objects may include buildings, parking garages, and trees.
  • the presence of these objects may require strategically placed base station antennas to provide adequate signal coverage in areas that might otherwise be in a blind spot.
  • To correctly locate base station antennas in a radio communications system it is important to be able to accurately predict signal strength, or another signal characteristic, in the service area when a base station antenna is placed in a particular location. Such a prediction is the goal of many so-called raytracing programs.
  • One problem with raytracing programs is that they don't accurately predict actual measured signal characteristics in the signal area. If a signal characteristic such as signal strength is over estimated, radio communications providers may spend more money than needed to provide communications services. On the other hand, if signal characteristics are under estimated, customers may be disappointed with the quality of services.
  • raytracing programs are not more accurate in producing a signal strength picture is because the model used to predict signal propagation does not take into account some characteristic of the environment that affects the signal.
  • current raytracing programs analyze propagating signals which are reflected by walls of buildings and diffracted by corners of buildings. In modeling the coverage area, raytracing programs represent building walls as objects or panels. Each panel has properties that describe the affects of a wall on a propagating signal. Such properties include reflection coefficients and mathematical expressions that describe radio wave diffraction at the corner of the panel.
  • FIG. 1 depicts a transmitted signal reflecting off of an object or panel, and an associated reflected image.
  • transmitter 20 is located relative to panel 22 in environment model 24.
  • Environment model 24 represents, for example, a portion of the coverage area having buildings that redirect propagating signals radiating from a transmitter antenna.
  • transmitter 20 is selected to radiate transmitted signals in a radiation pattern or arc 26 defined by rays 28 and 30.
  • transmitted signals propagate toward panel 22 and reflect off of panel 22 with a signal strength determined by the material of panel 22 and the incident angle between the ray and panel 22.
  • ray 28 reflects off of panel 22 to produce ray 32
  • ray 30 reflects to produce ray 34.
  • the signal strength of ray 32 depends upon the distance traveled by ray 28, incident angle 36, and the reflection coefficient of panel 22.
  • the signals reflected off of panel 22, such as ray 32 and 34 can be represented as conceptual or virtual rays coming from another point source, represented here by child image 38, which can be thought of as the origin of rays 32 and 34. Representing reflected signals as signals transmitted from a child image is a means for simplifying the raytracing problem.
  • a corner such as the corner of building 46 in FIG. 2
  • the transmitted signal is diffracted, as indicated by rays 48 and 50.
  • a corner which is called a diffraction corner, may occur at the end of a panel, such as the panels that make up building 46.
  • diffraction corner 52 may be represented by a child image at the same location, which, again, simplifies the raytracing problem.
  • FIG. 3 there is depicted a more complex environmental model of a communications system service area. If a system designer wants to know the total signal strength of a signal transmitted from transmitter 60 arriving at point of interest 62, the designer must consider signal power propagating directly from transmitter 60 to point of interest 62, as well as reflected and diffracted signal power arriving at point of interest 62. Thus, diffracted signals and signals reflecting off of buildings 64 and 66 may be modeled as rays coming from child images, and grandchild images.
  • the number of decendent images may be limited as specified by the user, or by an algorithm which considers the power contributed by each decendent image.
  • total signal strength at point of interest 62 may be calculated by accounting for contributions from transmitter 60 through ray 68, from child image 70 through ray 72, from child image 74 through ray 76, and from grandchild image 78 through ray 80.
  • Image 78 is referred to as a grandchild image because that image is a child of a child image. That is, grandchild image 78 is energized, or receives energy from, child image 70. Note that grandchild image 78 is not energized by transmitter 60 (the parent image) because the path between transmitter 60 and grandchild image 78 is obstructed by panel 82.
  • each node such as parent node 102, may point to, or be associated with, a child node, such as child nodes 104 and 106.
  • child nodes may point to a grandchild node
  • a grandchild node may point to a great grandchild node, such as grandchild node 108 and great grandchild node 110.
  • the same node, say node 108, may be a child node with respect to node 104 one level up, and a grandchild node with respect to node 102 two levels up.
  • these child-node expressions are relative expressions.
  • the environment model in FIG. 3 may be represented as a tree.
  • transmitter 60 may be represented in tree 100 as parent node 102.
  • Child image 70 in FIG. 3 may be represented as child node 104 in FIG. 4.
  • Child node 104 is associated with parent node 102 because child image 70 derives its energy from transmitter 60. It may be said that child image 70 energized or illuminated by transmitter 60.
  • child image 74 may be represented in tree 100 by child node 106.
  • Child nodes 104 and 106 have direct links to parent node 102 because child images 70 and 74 are directly energized by rays from transmitter 60 in FIG. 3.
  • Child image 78 is energized by a reflection off of building 64.
  • child image 78 is represented in tree 100 as grandchild node 108. Any rays emanating from child node 78 that strike additional panels to create child images will be represented as a great grandchild node, such as great grandchild node 110.
  • the parent image, or transmitter 60, and derivative child images in FIG. 3 may be represented by a tree, such as tree 100 in FIG. 4.
  • each node in tree 100 may be associated or linked with various types of data, including location of the node, type of node (reflection or diffraction), scope of the node (angles at which rays depart from the node).
  • This technique for organizing data allows the raytracing program to calculate the effects of each bounce or diffraction along the path between the transmitter and the point of interest.
  • FIG. 1 depicts a transmitted signal reflecting off of a panel
  • FIG. 2 depicts diffraction of a transmitted signal
  • FIG. 3 illustrates an environment model of a wireless system service area
  • FIG. 4 depicts a data structure for representing the propagation of radio frequency signals in a raytracing program
  • FIG. 5 illustrates a data processing system that may be used to implement the method and system of the present invention
  • FIG. 6 depicts an environment model of a wireless communications system that locates objects and attenuators in relation to a transmitter antenna in accordance with an embodiment of the method and system of the present invention
  • FIG. 7 is a high-level logical flowchart that illustrates the operation of an embodiment of the method and system of the present invention.
  • Data processing system 140 may include processor 142, keyboard 144, display 146, and pointing device
  • Keyboard 144 provides means for entering data and commands into processor 142.
  • Display 146 may be implemented utilizing any known means for displaying textual, graphical, or video images, such as a cathode ray tube (CRT), a liquid crystal display (LCD), an electroluminescent panel, or the like.
  • Pointing device 148 may be implemented utilizing any known pointing device, such as a trackball, joystick, touch sensitive tablet or screen, track pad, or as illustrated in FIG. 5, a mouse. Pointing device 148 may be utilized to move a pointer or a cursor on display 146.
  • Processor 142 may be coupled to one or more peripheral devices, such as CD-ROM 150.
  • Data processing system 140 includes means for reading data from a storage device. Such means for reading data may include: a hard disk drive internal or external to processor 142 (not shown); a tape drive (not shown); floppy disk drive 152, which reads and writes floppy disks 154; or CD-ROM 150, which reads and /or writes compact disk 156. Such storage means may be referred to as a computer usable medium for storing computer readable program code in the form of data and software. Data processing system 140 may also be coupled to a network which permits the transfer of data and software between data processing systems. Using such a network, programs can be loaded into data processing system 140.
  • data processing system 140 may each be implemented utilizing any one of several known off-the- shelf components.
  • data processing system 140 may be implemented utilizing any general purpose computer or so-called workstation, such as the workstation sold under the name "Model 712/60" by Hewlett-Packard Company of Palo Alto, CA.
  • workstation such as the workstation sold under the name "Model 712/60" by Hewlett-Packard Company of Palo Alto, CA.
  • workstation such as the workstation sold under the name "Model 712/60" by Hewlett-Packard Company of Palo Alto, CA.
  • Attenuator models may also be non-linear. This means that an attenuation factor per unit distance through the attenuator may depend upon where on the attenuator figure the radio frequency signal enters the attenuator, and the angle of incidence between the ray entering the attenuator and the surface of the attenuator.
  • a model of a tree may have a complex shape and a non-linear attenuation profile that depends upon the point of entry into the attenuator, the angle of entry, and the path through the attenuator.
  • FIG. 6 there is a depicted an environmental model of a wireless communications system that locates objects and attenuators in relation to a base station transmitter antenna in accordance with the method and system of the present invention.
  • transmitter antenna 200 is located near building 202.
  • buildings are formed by a plurality of panels.
  • building 204 includes panels 206 and 208 and additional panels (not shown) that form the other walls of building 204.
  • Building 210 includes panel 212.
  • Attenuators are trees 214 through 224.
  • attenuators may be any object that changes a characteristic, such as signal strength, of a radio frequency signal without changing the direction of propagation for at least a portion of the signal.
  • Other examples of attenuators include shrubs, billboards or signs, newsstands or other small structures, or other buildings that allow radio waves to propagate through, over, or around them.
  • trees may be represented by a compound three dimensional model that includes trunk 226 and foliage 218. Trunk 226 extends upward from the ground to a pre-selected height where the trunk ends and foliage 218 begins.
  • trunk 226 and foliage 218 are modeled with cylindrical shapes stacked one upon the other.
  • Other attenuating objects may be modeled with appropriate three dimensional figures.
  • the selected point of interest 228 is located in street 230.
  • Point of interest 228 is the point in the environment model that is used for calculating the transmitted signal characteristic, which in one embodiment of the present invention is signal strength.
  • signal strength which in one embodiment of the present invention is signal strength.
  • the three radio frequency signal propagation paths shown in FIG. 6 are labeled with reference numbers 232 through 236. Notice that each signal path includes a change of direction as a result of either a reflection or a diffraction.
  • Signal path 232 is reflected by panel 206.
  • Signal path 234 is diffracted by diffraction corner 238.
  • signal path 236 is reflected by panel 212.
  • Signal paths 232 and 236 are represented in a computer data structure with the aid of images 240 and 242, respectively.
  • the modeling technique used in the present invention uses rays from images in the environment model to illuminate the point of interest.
  • image 240 which is located opposite transmitter antenna 200 along a perpendicular line that intersects panel 206, emits ray 244, a conceptual or virtual ray that can illuminate or radiate radio frequency signal power on an object located at point of interest 228. Notice that a portion of ray 244 represents the portion of radio frequency signal propagation path 232 after it has been reflected off of panel 206.
  • Images 240 and 242 are represented in a data structure as locations in the environmental model from which radio frequency signals propagate.
  • diffraction corner 238 is also represented in the data structure as a source of radio frequency signals.
  • both radio frequency signal propagation paths 232 and 234 pass through an attenuator.
  • Propagation path 232 passes through trees 216 and 218, and path 234 passes through tree 218.
  • the attenuation of signal strength, or other variation in signal characteristic is dependent upon the distance traveled through the attenuator and the location of the propagation path in the attenuator.
  • propagation path 232 passes through an off-center portion of tree 216.
  • propagation path 232 does not pass through the trunk portion of tree 216.
  • propagation path 234 passes through the center of tree 218, and may also pass through trunk 226, depending upon the elevation of propagation path 234.
  • a signal that passes through the center of an attenuator may be attenuated at a different rate than a signal that passes through another portion of attenuator.
  • this is because a radio frequency signal that passes through the center of a tree is more likely to hit larger branches or portions of the trunk, which would appear as a different loss per meter than the loss per meter at the outer fringes of the tree's foliage which has fewer branches.
  • FIG. 7 there is depicted a high-level logical flow chart that illustrates the operation of an embodiment of the method and system of the present invention.
  • the process begins at block 300 and thereafter passes to block 302 wherein an environmental model of at least a portion of the wireless communications system is selected.
  • objects and attenuators are located relative to one another.
  • Objects include buildings and structures (which may be modeled with panels) that can redirect a propagating signal transmitted from a transmitter antenna. Such redirection of a signal occurs through reflection or diffraction.
  • Objects are used to model structures that are made of various materials. These materials are modeled with coefficients that are used to calculate the characteristics of reflected or diffracted signals. Thus, depending upon the material, reflected or diffracted signal characteristics are affected in different ways.
  • Attenuators include structures that modify a signal characteristic, such as signal strength, without substantially changing the direction of the propagating signal.
  • An example of an attenuator is a tree. Attenuators may be modeled as three dimensional figures, or as compound figures, as in the trees having a foliage part and a trunk part discussed above. These attenuators may also have an attenuation profile that describes how an attenuation factor varies depending upon the location of the signal path in the attenuator. This means that propagating signals passing through the center of a tree may be attenuated at a different rate than a signal propagating through the outer edge of a tree.
  • the parent image or transmitter image is located in the model, as depicted at block 304. Selection of the parent image is allowed so that proposed transmitter locations may be evaluated for signal coverage in the environment model.
  • the process creates a data structure, such as a binary tree data structure, that represents radio frequency signal propagation paths using rays from images that are illuminated by an associated parent image, as illustrated at block 306.
  • a data structure such as a binary tree data structure
  • that image receives its signal power from an associated parent image.
  • image 240 is illuminated by its parent image, transmitter antenna 200.
  • the association between image 240 and its parent, transmitter antenna 200 may be illustrated by the fact that image 240 would not exist if transmitter antenna 200 was not there.
  • Points of interest are typically selected at locations where a subscriber unit is likely to be found.
  • point of interest 228 is selected in street 230.
  • a point of interest is iteratively selected at different locations in the environment model.
  • an image that represents at least a portion of a radio frequency signal path from an associated parent image to the point of interest is selected, as illustrated at block 310.
  • One way to select such an image is to look for an image, from the point of view of the point of interest, that is not blocked by another panel (not counting the panel responsible for generating the reflected image). For example, in FIG. 6, three images are visible from point of interest 228 — images 240 and 242, and diffraction corner 238.
  • the process determines whether or not the radio frequency signal propagation path associated with the selected image passes through an attenuator, as depicted at block 312. Thus, if image 240 is the selected image, the process determines whether or not the signal propagation path associated with image 240 — signal path 232 — intersects or passes through an attenuator. In the case of signal path 232, the signal passes through two attenuators — tree 216 along a leg of signal path 232 that is before the reflection, and tree 218 along the leg of signal path 232 after the reflection.
  • signal path 232 may be analyzed in three dimensions.
  • the process may determine whether or not signal path 232 passes above or below the foliage of tree 216.
  • the process may determine whether or not the signal path passes through the foliage portion of a tree or the trunk portion of a tree.
  • the process calculates the distance that the propagating signal traveled through such an attenuator, as illustrated at block 314.
  • the attenuator is modeled as a cylinder
  • this involves calculating the length of a chord formed by the intersection of the cylinder and a line representing the signal path. That is, calculating the length of the line between the entry point and the exit point of the attenuator.
  • the process determines the attenuation factor based upon the attenuator profile, as depicted at block 316.
  • Such an attenuator profile describes how the attenuator attenuates a propagating signal depending upon the location of the signal path in the attenuator.
  • Such an attenuator profile may specify, for example, that a signal passing through the center of a tree is attenuated more per unit distance than a signal entering the fringes or outer edges of the tree.
  • Such an attenuator profile may also include information about signal attenuation based upon an incident angle between the signal path and the surface of the attenuator. Such an incident angle may require more analysis when the angle is not so predictable, as when the shape of the attenuator is a polygon rather than a circle
  • the process calculates the radio frequency signal attenuation that results from passing through the attenuator, as illustrated at block 318.
  • radio frequency signal attenuation other signal characteristics may be calculated as a result of more complex models which combine signal scattering from leaves, diffraction, reflection, transmission, and attenuation, in combination for the estimated sizes, density and distribution of the leaves.
  • Statistical averages relating the radio frequency properties may also be used on tree parameters, including foliage density, moisture content, size, shape, and type of tree.
  • the process calculates the radio frequency signal attenuation due to signal path length, including signal paths before and after any reflections or diffractions, and attenuation due to any reflections or diffractions, as depicted at block 320.
  • the radio frequency signal attenuation due to free air propagation between transmitter antenna 200 and panel 206, and between panel 206 and point of interest 228 are calculated.
  • any attenuation that occurs during the reflection off of panel 206 is also calculated.
  • the process accounts for all calculated losses in signal strength along the radio frequency signal propagation path from the parent image to the point of interest, as illustrated at block 322.
  • This accounting includes losses calculated in block 320 and in block 318 if the propagation path passes through an attenuator.
  • the process may loop from block 322 back to block 310 to select additional images that are capable of illuminating the selected point of interest. This allows signal strength calculations at a point of interest to consider signal power received from multiple signal propagation paths. Examples of other images that can illuminate point of interest 228 include image 242, which is associated with a path that does not pass through an attenuator, and image 238, which is a diffraction corner associated with a signal path that passes through tree 218, and maybe through trunk 226. Additionally, the process may also iteratively loop back from block
  • aspects of this invention pertain to specific method functions implementable on computer systems.
  • the invention may be implemented as a computer program product for use with a computer or data processing system.
  • programs defining the functions of the present invention can be delivered to a computer in many forms, which include, but are not limited to: (1) information permanently stored in non-writable storage media (e.g. read-only memory devices such as ROM chips, or CD-ROM disks 156 — readable by a computer I/O attachment such as CD-ROM reader 150); (2) information alterably stored on writable storage media (e.g.
  • hard disk drives and floppy disks 154 ); or (3) information conveyed to a computer through communication media, such as a network, the public switched telephone network, a fiber optic cable, and transmitted radio frequency signals. It should be understood, therefore, that such media, when carrying computer readable instructions that direct the method functions of the present invention, represent alternate embodiments of the present invention.
  • the method and system of the present invention more accurately predicts transmitted signal characteristics, such as signal strength, in a model of a communications system service area. More accurate predictions enable system designers to provide quality communications services without the cost of over designing the system with overlapping signal coverage between cell sites. More accurate predictions also expose signal coverage problems, which may then be fixed before customers are annoyed by poor service.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Quality & Reliability (AREA)
  • Monitoring And Testing Of Transmission In General (AREA)

Abstract

Un modèle d'environnement dans lequel au moins un objet (206) et au moins un atténuateur (218) sont positionnés par rapport à un émetteur (200) est sélectionné. Une structure de données (100) qui représente des chemins de propagation de signaux radiofréquence (234) au moyen de rayons (244) émanant d'images dans ledit modèle est créée, les images (240) étant illuminées par les signaux radiofréquence provenant d'images parentes (200). Un point d'intérêt (228) est sélectionné dans le modèle de l'environnement. Une image (240) représentant un chemin de propagation de signaux radiofréquence (234) jusqu'audit point d'intérêt (228) est sélectionnée au moyen de la structure de données (100). On calcule une variation de la caractéristique du signal transmis en déterminant si le chemin de propagation du signal radiofréquence passe par l'atténuateur (218) et en calculant une variation de la caractéristique du signal causée par la propagation de ce dernier à travers l'atténuateur (218). Enfin, la caractéristique du signal transmis au niveau dudit point d'intérêt choisi (228) est calculée en réponse à la variation calculée de ladite caractéristique.
PCT/US1997/008569 1996-07-23 1997-05-21 Procede et systeme de calcul d'une caracteristique de signal transmis dans un modele d'environnement comportant des elements attenuateurs WO1998004059A1 (fr)

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US08/685,344 1996-07-23

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EP1314097A4 (fr) * 2000-07-28 2005-11-30 Wireless Valley Comm Inc Systeme, procede et appareil portable pour conception, developpement, test et optimisation d'un reseau de communication
WO2006116766A1 (fr) * 2005-04-27 2006-11-02 The Regents Of The University Of California Modele statistique et procede de simulation de propagation rf dans des environnements urbains bases sur la physique
KR20190036435A (ko) * 2017-09-27 2019-04-04 삼성전자주식회사 수목을 고려한 통신 환경 분석 및 망 설계를 위한 방법 및 장치
WO2019066391A1 (fr) 2017-09-27 2019-04-04 Samsung Electronics Co., Ltd. Procédé et appareil d'analyse d'environnements de communication et de conception de réseaux en tenant compte de la présence d'arbres
CN111164913A (zh) * 2017-09-29 2020-05-15 三星电子株式会社 用于分析无线通信系统中的通信环境的方法和装置
CN111418167A (zh) * 2017-12-18 2020-07-14 三星电子株式会社 考虑可移动物体的通信环境分析和网络设计的方法和装置

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Cited By (16)

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EP1314097A4 (fr) * 2000-07-28 2005-11-30 Wireless Valley Comm Inc Systeme, procede et appareil portable pour conception, developpement, test et optimisation d'un reseau de communication
WO2006116766A1 (fr) * 2005-04-27 2006-11-02 The Regents Of The University Of California Modele statistique et procede de simulation de propagation rf dans des environnements urbains bases sur la physique
US7796983B2 (en) 2005-04-27 2010-09-14 The Regents Of The University Of California Physics-based statistical model and simulation method of RF propagation in urban environments
EP3659276A4 (fr) * 2017-09-27 2020-07-22 Samsung Electronics Co., Ltd. Procédé et appareil d'analyse d'environnements de communication et de conception de réseaux en tenant compte de la présence d'arbres
WO2019066391A1 (fr) 2017-09-27 2019-04-04 Samsung Electronics Co., Ltd. Procédé et appareil d'analyse d'environnements de communication et de conception de réseaux en tenant compte de la présence d'arbres
CN111149309A (zh) * 2017-09-27 2020-05-12 三星电子株式会社 考虑树的通信环境分析和网络设计方法及设备
KR20190036435A (ko) * 2017-09-27 2019-04-04 삼성전자주식회사 수목을 고려한 통신 환경 분석 및 망 설계를 위한 방법 및 장치
KR102442461B1 (ko) * 2017-09-27 2022-09-14 삼성전자 주식회사 수목을 고려한 통신 환경 분석 및 망 설계를 위한 방법 및 장치
US11467148B2 (en) 2017-09-27 2022-10-11 Samsung Electronics Co., Ltd. Method and apparatus for analyzing communication environments and designing networks in consideration of trees
CN111164913A (zh) * 2017-09-29 2020-05-15 三星电子株式会社 用于分析无线通信系统中的通信环境的方法和装置
CN111164913B (zh) * 2017-09-29 2022-08-23 三星电子株式会社 用于分析无线通信系统中的通信环境的方法和装置
US11539450B2 (en) 2017-09-29 2022-12-27 Samsung Electronics Co., Ltd. Method and apparatus for analyzing communication environment in wireless communication system
CN111418167A (zh) * 2017-12-18 2020-07-14 三星电子株式会社 考虑可移动物体的通信环境分析和网络设计的方法和装置
EP3683985A4 (fr) * 2017-12-18 2020-11-25 Samsung Electronics Co., Ltd. Procédé et appareil d'analyse d'environnement de communication et de conception de réseau prenant en compte un objet mobile
US11463185B2 (en) 2017-12-18 2022-10-04 Samsung Electronics Co., Ltd. Method and apparatus for communication environment analysis and network design considering movable object
CN111418167B (zh) * 2017-12-18 2023-05-23 三星电子株式会社 考虑可移动物体的通信环境分析和网络设计的方法和装置

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