Big Data Computing: Quiz Assignment-IV Solutions (Week-4)

1. Identify the correct choices for the given scenarios:
P: The system allows operations all the time, and operations return quickly
Q: All nodes see same data at any time, or reads return latest written value by any client R: 

The system continues to work in spite of network partitions
A. P: Consistency, Q: Availability, R: Partition tolerance
B. P: Availability, Q: Consistency, R: Partition tolerance
C. P: Partition tolerance, Q: Consistency, R: Availability
D. P: Consistency, Q: Partition tolerance, R: Availability
 

Answer: B) P: Availability, Q: Consistency, R: Partition tolerance 

Explanation:
CAP Theorem states following properties:
Consistency: All nodes see same data at any time, or reads return latest written value by any client.
Availability: The system allows operations all the time, and operations return quickly.
Partition-tolerance: The system continues to work in spite of network partitions.

2. Cassandra uses a protocol called to discover location and state information about the other nodes participating in a Cassandra cluster.
A. Key-value
B. Memtable
C. Heartbeat
D. Gossip

Answer: D) Gossip

Explanation: Cassandra uses a protocol called Gossip to obtain information about the location and status of the other nodes participating in a Cassandra cluster. Gossip is a peer-to-peer communication protocol in which nodes regularly exchange status information about themselves and about other nodes they know.


3. In Cassandra, is used to specify data centers and the number of replicas to place within each data center. It attempts to place replicas on distinct racks to avoid the node failure and to ensure data availability.
A. Simple strategy
B. Quorum strategy
C. Network topology strategy
D. None of the mentioned 

Answer: C) Network topology strategy

Explanation: The network topology strategy is used to specify the data centers and the number of replicas to be placed in each data center. Try to place replicas in different racks to avoid node failure and ensure data availability. In the network topology strategy, the two most common methods for configuring multiple data center clusters are: two replicas in each data center and three replicas in each data center.

 

4. True or False ?
A Snitch determines which data centers and racks nodes belong to. Snitches inform Cassandra about the network topology so that requests are routed efficiently and allows Cassandra to distribute replicas by grouping machines into data centers and racks.
A. True
B. False

Answer: True

Explanation: A snitch determines which data centers and rack nodes they belong to. The snitches inform Cassandra about the network topology so that requests can be routed efficiently and Cassandra can distribute replicas by grouping machines in data centers and racks. In particular, the replication strategy places the replicas based on the information provided by the new Snitch. All nodes must return to the same rack and data center. Cassandra tries her best not to have more than one replica on the same shelf (which is not necessarily a physical location).


5. Consider the following statements:
Statement 1: In Cassandra, during a write operation, when hinted handoff is enabled and If any replica is down, the coordinator writes to all other replicas, and keeps the write locally until down replica comes back up.
Statement 2: In Cassandra, Ec2Snitch is important snitch for deployments and it is a simple snitch for Amazon EC2 deployments where all nodes are in a single region. In Ec2Snitch region name refers to data center and availability zone refers to rack in a cluster.
A. Only Statement 1 is true
B. Only Statement 2 is true
C. Both Statements are true
D. Both Statements are false

Answer: C) Both Statements are true

Explanation: Cassandra uses a protocol called Gossip to obtain information about the location and status of the other nodes participating in a Cassandra cluster. Gossip is a peer-to-peer communication protocol in which nodes regularly exchange status information about themselves and about other nodes they know.

 

6. What is Eventual Consistency ?
A. At any time, the system is linearizable
B. If writes stop, all reads will return the same value after a while
C. At any time, concurrent reads from any node return the same values
D. If writes stop, a distributed system will become consistent

Answer: B) If writes stop, all reads will return the same value after a while

Explanation: Cassandra offers Eventual Consistency. Is says that If writes to a key stop, all replicas of key will converge automatically.

 

7. Consider the following statements:
Statement 1: When two processes are competing with each other causing data corruption, it is called deadlock
Statement 2: When two processes are waiting for each other directly or indirectly, it is called race condition
A. Only Statement 1 is true
B. Only Statement 2 is true
C. Both Statements are false
D. Both Statements are true 

Answer: C) Both Statements are false 

Explanation: The correct statements are:
Statement 1: When two processes are competing with each other causing data corruption, it is called Race Condition
Statement 2: When two processes are waiting for each other directly or indirectly, it is called deadlock.


8. ZooKeeper allows distributed processes to coordinate with each other through registers, known as
A. znodes
B. hnodes
C. vnodes
D. rnodes

Answer: A) znodes

Explanation: Every znode is identified by a path, with path elements separated by a slash.



9. In Zookeeper, when a is triggered the client receives a packet saying that the znode has changed.
A. Event
B. Row
C. Watch
D. Value

Answer: C) Watch

Explanation: ZooKeeper supports the concept of watches. Clients can set a watch on a znodes.


10. Consider the Table temperature_details in Keyspace “day3” with schema as follows:
temperature_details(daynum, year,month,date,max_temp)
with primary key(daynum,year,month,date) 

DayNum	Year	Month	Date	MaxTemp (°C)
1	1943	10	1	14.1
2	1943	10	2	16.4
541	1945	3	24	21.1
9970	1971	1	16	21.4
20174	1998	12	24	36.7
21223	2001	11	7	16
4317	1955	7	26	16.7

 There exists same maximum temperature at different hours of the same day. Choose the correct CQL query to:

Alter table temperature_details to add a new column called “seasons” using map of type
<varint, text> represented as <month, season>. Season can have the following values season={spring, summer, autumn, winter}.
Update table temperature_details where columns daynum, year, month, date contain the following values- 4317,1955,7,26 respectively.
Use the select statement to output the row after updation.
Note: A map relates one item to another with a key-value pair. For each key, only one value may exist, and duplicates cannot be stored. Both the key and the value are designated with a data type.

A)
cqlsh:day3> alter table temperature_details add hours1 set<varint>;
cqlsh:day3> update temperature_details set hours1={1,5,9,13,5,9} where daynum=4317; cqlsh:day3> select * from temperature_details where daynum=4317;


B)
cqlsh:day3> alter table temperature_details add seasons map<varint,text>;
cqlsh:day3> update temperature_details set seasons = seasons + {7:'spring'} where daynum=4317 and year =1955 and month = 7 and date=26;
cqlsh:day3> select * from temperature_details where daynum=4317 and year=1955 and month=7 and date=26;


C)
cqlsh:day3>alter table temperature_details add hours1 list<varint>;
cqlsh:day3> update temperature_details set hours1=[1,5,9,13,5,9] where daynum=4317 and year = 1955 and month = 7 and date=26;
cqlsh:day3> select * from temperature_details where daynum=4317 and year=1955 and month=7 and date=26;


D) cqlsh:day3> alter table temperature_details add seasons map<month, season>;
cqlsh:day3> update temperature_details set seasons = seasons + {7:'spring'} where daynum=4317;
cqlsh:day3> select * from temperature_details where daynum=4317;

Answer: B)
cqlsh:day3> alter table temperature_details add seasons map<varint,text>;
cqlsh:day3> update temperature_details set seasons = seasons + {7:'spring'} where daynum=4317 and year =1955 and month = 7 and date=26;
cqlsh:day3> select * from temperature_details where daynum=4317 and year=1955 and month=7 and date=26;


Explanation:
The correct steps are:
a) Add column “seasons”
cqlsh:day3> alter table temperature_details add seasons map<varint,text>;

b) Update table
cqlsh:day3> update temperature_details set seasons = seasons + {7:'spring'} where daynum=4317 and year =1955 and month = 7 and date=26;

c) Select query
cqlsh:day3> select * from temperature_details where daynum=4317 and year=1955 and month=7 and date=26;

 

daynum	year	month	date	hours	hours1	max_temp	seasons
4317	1955	7	26	{1,5,9,13}	[1,5,9,13,5,9]	16.7	{7:’spring’}

Big Data Computing: Quiz Assignment-III Solutions (Week-3)

1. In Spark, a is a read-only collection of objects partitioned across a set of machines that can be rebuilt if a partition is lost.

A. Spark Streaming

B. FlatMap

C. Driver

D. Resilient Distributed Dataset (RDD)

Answer: D) Resilient Distributed Dataset (RDD)

Explanation: Resilient Distributed Data Sets (RDDs) are a basic Spark data structure. It is a distributed and immutable collection of objects. Each dataset in RDD is divided into logical partitions that can be computed on different nodes in the cluster. RDDs can contain any type of Python, Java, or Scala object, including custom classes. Formally, an RDD is a read-only, partitioned collection of data sets. RDDs can be created by deterministic operations on data in stable storage or other RDDs. RDD is a collection of fault tolerant elements that can be operated in parallel.

2. Given the following definition about the join transformation in Apache Spark:

def join[W](other: RDD[(K, W)]): RDD[(K, (V, W))]

Where join operation is used for joining two datasets. When it is called on datasets of type (K, V) and (K, W), it returns a dataset of (K, (V, W)) pairs with all pairs of elements for each key.

Output the result of joinrdd, when the following code is run.

val rdd1 = sc.parallelize(Seq(("m",55),("m",56),("e",57),("e",58),("s",59),("s",54)))

val rdd2 = sc.parallelize(Seq(("m",60),("m",65),("s",61),("s",62),("h",63),("h",64))) val joinrdd = rdd1.join(rdd2)

joinrdd.collect

A. Array[(String, (Int, Int))] = Array((m,(55,60)), (m,(55,65)), (m,(56,60)),

(m,(56,65)), (s,(59,61)), (s,(59,62)), (h,(63,64)), (s,(54,61)), (s,(54,62)))

B. Array[(String, (Int, Int))] = Array((m,(55,60)), (m,(55,65)), (m,(56,60)),

(m,(56,65)), (s,(59,61)), (s,(59,62)), (e,(57,58)), (s,(54,61)), (s,(54,62)))

C. Array[(String, (Int, Int))] = Array((m,(55,60)), (m,(55,65)), (m,(56,60)),

(m,(56,65)), (s,(59,61)), (s,(59,62)), (s,(54,61)), (s,(54,62)))

D. None of the mentioned

Answer: C) Array[(String, (Int, Int))] = Array((m,(55,60)), (m,(55,65)), (m,(56,60)),

(m,(56,65)), (s,(59,61)), (s,(59,62)), (s,(54,61)), (s,(54,62)))

Explanation: join() is transformation which returns an RDD containing all pairs of elements with matching keys in this and other. Each pair of elements will be returned as a (k, (v1, v2)) tuple, where (k, v1) is in this and (k, v2) is in other.

 

3. Consider the following statements in the context of Spark:

Statement 1: Spark improves efficiency through in-memory computing primitives and general computation graphs.

Statement 2: Spark improves usability through high-level APIs in Java, Scala, Python and also provides an interactive shell.

A. Only statement 1 is true

B. Only statement 2 is true

C. Both statements are true

D. Both statements are false

Answer: C) Both statements are true

Explanation: Apache Spark is a fast and universal cluster computing system. It offers high-level APIs in Java, Scala, and Python, as well as an optimized engine that supports general-execution graphics. It also supports a variety of higher-level tools, including Spark SQL for SQL and structured computing, MLlib for machine learning, GraphX ​​for graph processing, and Spark Streaming. Spark comes with several sample programs. Spark offers an interactive shell, a powerful tool for interactive data analysis. It is available in Scala or Python language. Spark improves efficiency through in-memory computing primitives. With in-memory computing, data is kept in random access memory (RAM) instead of some slow disk drives and is processed in parallel. This allows us to recognize a pattern and analyze large amounts of data. This has become popular because it reduces the cost of storage. Therefore, in-memory processing is economical for applications.

4. True or False ?

Resilient Distributed Datasets (RDDs) are fault-tolerant and immutable.

A. True

B. False

Answer: True

Explanation: Resilient Distributed Datasets (RDDs) are:

1. Immutable collections of objects spread across a cluster

2. Built through parallel transformations (map, filter, etc.)

3. Automatically rebuilt on failure

4. Controllable persistence (e.g. caching in RAM)

5. Which of the following is not a NoSQL database?

A. HBase

B. Cassandra

C. SQL Server

D. None of the mentioned

Answer: C) SQL Server

Explanation: NoSQL, which stands for "not just SQL", is an alternative to traditional relational databases where the data is stored in tables and the data schema is carefully designed before the database is created. NoSQL databases are particularly useful for working with large amounts of distributed data.

 

6. True or False ?

Apache Spark potentially run batch-processing programs up to 100 times faster than Hadoop MapReduce in memory, or 10 times faster on disk.

A. True

B. False

Answer: True

Explanation: Spark's biggest claim about speed is that "it can run programs up to 100 times faster than Hadoop MapReduce in memory or 10 times faster on disk." Spark could make this claim because it takes care of the processing in the main memory of the worker nodes and avoids unnecessary I / O operations on the disks. The other benefit that Spark offers is the ability to chain tasks at the application programming level without actually writing to disks or minimizing the amount of writes to disks.

7. _____________leverages Spark Core fast scheduling capability to perform streaming analytics.

A. MLlib

B. Spark Streaming

C. GraphX

D. RDDs

Answer: B) Spark Streaming

Explanation: Spark Streaming ingests data in mini-batches and performs RDD transformations on those mini-batches of data.

8. _________ is a distributed graph processing framework on top of Spark.

A. MLlib

B. Spark streaming

C. GraphX

D. All of the mentioned

Answer: C) GraphX

Explanation: GraphX is Apache Spark's API for graphs and graph-parallel computation. It is a distributed graph processing framework on top of Spark.

9. Point out the incorrect statement in the context of Cassandra:

A. It is a centralized key-value store

B. It is originally designed at Facebook

C. It is designed to handle large amounts of data across many commodity servers, providing high availability with no single point of failure

D. It uses a ring-based DHT (Distributed Hash Table) but without finger tables or routing

Answer: A) It is a centralized key-value store

Explanation: Cassandra is a distributed key-value store.

10. Consider the following statements:

Statement 1: Scale out means grow your cluster capacity by replacing with more powerful machines.

Statement 2: Scale up means incrementally grow your cluster capacity by adding more COTS machines (Components Off the Shelf).

A. Only statement 1 is true

B. Only statement 2 is true

C. Both statements are false

D. Both statements are true

Answer: C) Both statements are false

Explanation: The correct statements are:

Scale up = grow your cluster capacity by replacing with more powerful machines

Scale out = incrementally grow your cluster capacity by adding more COTS machines (Components Off the Shelf)

Big Data Computing: Quiz Assignment-II Solutions (Week-2)

1. Consider the following statements:

Statement 1: The Job Tracker is hosted inside the master and it receives the job execution request from the client.

Statement 2: Task tracker is the MapReduce component on the slave machine as there are multiple slave machines.

A. Only statement 1 is true

B. Only statement 2 is true

C. Both statements are true

D. Both statements are false

Answer: C) Both statements are true

2. _______________is the slave/worker node and holds the user data in the form of Data Blocks.

A. NameNode

B. Data block

C. Replication

D. DataNode

Answer: D) DataNode

Explanation: The NameNode acts as the main server that manages the namespace of the file system, primarily managing client access to these files, and also keeping track of the location of the data on the DataNode and the basic distribution location of blocks. On the other hand, DataNode is a slave / worker node and stores user data in the form of data blocks.

3. ________works as a master server that manages the file system namespace and basically regulates access to these files from clients, and it also keeps track of where the data is on the Data Nodes and where the blocks are distributed essentially.

A. Name Node

B. Data block

C. Replication

D. Data Node

Answer: A) Name Node

Explanation: Namenode, as the main server, manages the namespace of the file system, and basically regulates the client's access to these files. At the same time, it also tracks the location of the data on the data node and the basic distribution location of the block. On the other hand, data nodes are slave/work nodes, which contain user data in the form of data blocks.

4. The number of maps in MapReduce is usually driven by the total size of

A. Inputs

B. Outputs

C. Tasks

D. None of the mentioned

Answer: A) Inputs

Explanation: The map, written by the user takes a pair of entry and produces a series of intermediate keys / value pairs. The MapReduce Library groups together all the intermediate values associated with the same intermediate key "I 'and pass them to the function reduce.

5. True or False ?

The main duties of task tracker are to break down the receive job that is big computations in small parts, allocate the partial computations that is tasks to the slave nodes monitoring the progress and report of task execution from the slave.

A. True

B. False

Answer: B) False

Explanation: The task tracker will communicate the progress and report the results to the job tracker.

6. Point out the correct statement in context of YARN:

A. YARN is highly scalable.

B. YARN enhances a Hadoop compute cluster in many ways

C. YARN extends the power of Hadoop to incumbent and new technologies found within the data center

D. All of the mentioned

Answer: D) All of the mentioned

7. Consider the pseudo-code for MapReduce's WordCount example (not shown here). Let's now assume that you want to determine the frequency of phrases consisting of 3 words each instead of determining the frequency of single words. Which part of the (pseudo-)code do you need to adapt?

A. Only map()

B. Only reduce()

C. map() and reduce()

D. The code does not have to be changed

Answer: A) Only map()

Explanation: The map function takes a value and outputs key:value pairs.

For instance, if we define a map function that takes a string and outputs the length of the word as the key and the word itself as the value then

map(steve) would return 5:steve and map(savannah) would return 8:savannah.

This allows us to run the map function against values in parallel. So we have to only adapt the map() function of pseudo code.

8. The namenode knows that the datanode is active using a mechanism known as

A. Heartbeats

B. Datapulse

C. h-signal

D. Active-pulse

Answer: A) heartbeats

Explanation: Use Heartbeat to communicate between the Hadoop Namenode and Datanode. Heartbeat is therefore a signal that the data node sends to the name node after a certain time interval to indicate its existence, ie to indicate that it is alive.

9. True or False ?

HDFS performs replication, although it results in data redundancy?

A. True

B. False

Answer: True

Explanation: Once the data has been written on HDFS, it is replicated immediately along the cluster, so that the different data copies are stored in different data nodes. Normally, the replication factor is 3, since due to this, the data does not remain on replicates or are lower.

10. _____________function processes a key/value pair to generate a set of intermediate key/value pairs.

A. Map

B. Reduce

C. Both Map and Reduce

D. None of the mentioned

Answer: A) Map

Explanation: Mapping is a single task that converts input data records into intermediate data records and reduces the process and merges all intermediate values ​​assigned by each key.

Big Data Computing: Quiz Assignment-I Solutions (Week-1)

1. _____________is responsible for allocating system resources to the various applications running in a Hadoop cluster and scheduling tasks to be executed on different cluster nodes.

A. Hadoop Common
B. Hadoop Distributed File System (HDFS)
C. Hadoop YARN
D. Hadoop MapReduce

Answer: C) Hadoop YARN

Explanation:

Hadoop Common: Contains libraries and utilities necessary from other Didoop modules.
HDFS: It is a distributed file system that stores data on a commodity machine. Provide a very high addition bandwidth throughout the cluster.
Hadoop Discussion: is a resource management platform responsible for managing processing resources in the cluster and use them to schedule users and applications. The thread is responsible for the assignment of system resources to the various applications running in a Hadoop cluster and the programming activities that are performed in different clustered nodes.
Hadooop MapReduce: it is a programming model that resizes data into many different processes.

 

2. Which of the following tool is designed for efficiently transferring bulk data between Apache Hadoop and structured datastores such as relational databases ?
A. Pig
B. Mahout
C. Apache Sqoop
D. Flume

Answer: C) Apache Sqoop

Explanation: Apache Sqoop is a tool designed for efficiently transferring bulk data between Apache Hadoop and structured datastores such as relational databases

 

3. ________________is a distributed, reliable, and available service for efficiently collecting, aggregating, and moving large amounts of log data.
A. Flume
B. Apache Sqoop
C. Pig
D. Mahout

Answer: A) Flume
Explanation: Flume is a distributed, reliable, and available service for efficiently collecting, aggregating, and moving large amounts of historical data. It has a simple and very flexible architecture based on streaming data flow. It is very robust and fault-tolerant, and can really be adjusted to improve reliability mechanisms, failover, recovery, and any other mechanisms that keep the cluster safe and reliable. It uses a simple extensible data model that allows us to use various online analysis applications.

 

4. _____________refers to the connectedness of big data.

A. Value
B. Veracity
C. Velocity
D. Valence

Answer: D) Valence

Explanation: Valence refers to the connectedness of big data. Such as in the form of graph networks

 

5. Consider the following statements:

Statement 1: Volatility refers to the data velocity relative to timescale of event being studied

Statement 2: Viscosity refers to the rate of data loss and stable lifetime of data

A. Only statement 1 is true
B. Only statement 2 is true
C. Both statements are true
D. Both statements are false

Answer: D) Both statements are false

Explanation: The correct statements are:

Statement 1: Viscosity refers to the data velocity relative to timescale of event being studied Statement 2: Volatility refers to the rate of data loss and stable lifetime of data

 

6.___________refers to the biases, noise and abnormality in data, trustworthiness of data.

A. Value
B. Veracity
C. Velocity
D. Volume

Answer: B) Veracity

Explanation: Veracity refers to the biases ,noise and abnormality in data, trustworthiness of data.

 

7. ___________brings scalable parallel database technology to Hadoop and allows users to submit low latencies queries to the data that's stored within the HDFS or the Hbase without acquiring a ton of data movement and manipulation.
A. Apache Sqoop
B. Mahout
C. Flume
D. Impala

Answer: D) Impala

Explanation: Cloudera, Impala is specially designed for Cloudera, it is a query engine that runs on Apache Hadoop. The project was officially announced in late 2012 and became a publicly available open source distribution. Impala brings scalable parallel database technology to Hadoop, allowing users to send low-latency queries to data stored in HDFS or Hbase without performing a lot of data movements and operations.

 

8. True or False ?

NoSQL databases store unstructured data with no particular schema
A. True
B. False

Answer: A) True
Explanation: Traditional SQL can handle a large amount of structured data effectively, and we need NoSQL (not only SQL) to handle unstructured data. NoSQL database stores unstructured data without a specific schema.

 

9. _____________is a highly reliable distributed coordination kernel , which can be used for distributed locking, configuration management, leadership election, and work queues etc.
A. Apache Sqoop
B. Mahout
C. ZooKeeper
D. Flume

Answer: C) ZooKeeper

Explanation: Zookeeper is a central key value store that uses distributed systems that can coordinate. Since it is necessary to be able to manage the load, the zookeeper works with many machines.

 

10. True or False ?

MapReduce is a programming model and an associated implementation for processing and generating large data sets.
A. True
B. False

Answer: A) True

Mobile Adhoc Network and its types

Mobile Ad Hoc Network

Among the entire communication networks available today, the popularity of wireless networks has recently been appreciated for their wide applicability and versatility. It completely changed science and technology, and added convenience and beauty to modern life. Due to the convergence of wireless technology and traditional wired devices, complex technologies have become simpler and easier to use. Wireless technology is integrated with our personal and professional lives in the form of mobile phones, wireless fidelity (WiFi), Bluetooth, tele-medicine, etc. Today, we completely rely on these types of devices and applications to meet our comfort and needs. Various wireless networks exist, from the most popular infrastructure-based cellular networks to the latest and most advanced self-organizing and sensor networks.

Mobile Ad Hoc Network [MANET] is a decentralized network in which mobile nodes are connected via wireless links without any pre-established infrastructure. The high degree of freedom and self-organization capabilities make it completely different from other networks. It is one of the most challenging and innovative areas in wireless networks, with many applications in different areas. These applications are suitable for disaster management, rescue operations, vehicle networks, agricultural sensors, pollution monitoring, and more. Ad hoc networks improve the efficiency of fixed and mobile Internet access and support new applications such as sensors and mesh networks. With its significant advantages over traditional wired networks, there are still unsolved challenges such as unpredictable mobility, limited battery power, limited bandwidth, multi-hop routing, dynamic topology, and security. Among them, the effective use of energy is one of the important issues because the nodes are powered by batteries. Energy efficiency remains a key performance indicator, because effective energy use can extend the life of the network, so increasing network capacity is critical. Therefore, people strive to reduce energy consumption in different ways. Recently, it has been reported in the literature that power saving can be realized at all layers of the network protocol stack. Different studies have proposed different techniques to address energy problems in different ways. In this article, we propose three techniques to reduce power consumption at the protocol level. The first technique reduces power consumption by logically dividing the network, while the second technique applies power control at the node level to reduce the transmit power of the node. In topology control technology, inefficient links are eliminated to increase network capacity.

(MANET) is a non-infrastructure network that is continually self-configuring and is comprised of wireless connected mobile devices. Ad hoc is Latin and means "for this purpose". Each device in MANET can move independently in any direction freely, so its links with other devices are frequently changed. Each must forward traffic unrelated to its own use, and therefore must be a router. The main challenge in building MANET is to equip each device to continuously maintain the information needed to route traffic correctly. These networks can operate independently, or they can be connected to a larger Internet. They can contain one or more different transceivers between nodes. This leads to a highly dynamic autonomous topology. MANET is a special wireless network, which usually has a rout-able network environment on a special link layer network. Compared with a mesh network with a central controller (used to determine, optimize, and distribute routing tables), MANET consists of a self-formed, self-healing peer-to-peer network. MANET around 2000-2015 usually communicated on a radio frequency (30MHz).

Since the mid-1990s, the development of notebook computers and 802.11/WiFi wireless networks has made MANET a hot research topic. Many academic articles evaluate the protocols and their capabilities, assuming varying degrees of mobility in a delimited space, generally, all nodes are within a few jumps of each other. Then evaluate the different protocols based on measures such as packet loss rate, overhead introduced by routing protocols, end-to-end packet delay, network performance, and scalability.

 

Types of MANET

• Vehicle Ad Hoc Network (VANET) is used for communication between vehicles and road equipment. Intelligent Vehicle Self-Organizing Networks (in VANET) are a type of artificial intelligence that can help vehicles behave intelligently during vehicle collisions and accidents.

• Smart Phone Ad Hoc Networks (SPAN) uses existing hardware (primarily Bluetooth and WiFi) in business smartphones to create peer-to-peer networks without relying on cellular carrier networks, wireless access points, or traditional network infrastructure. SPAN is different from traditional hub and radio networks (such as WiFi Direct) in that they support multi-hop relay and there is no concept of group leader, so peers can join and leave at will without disrupting the network.

• Internet-based mobile ad hoc network (iMANET) is an ad hoc network linking mobile nodes and fixed Internet gateway nodes. For example, in a classic HubSpoke VPN, multiple subMANETs can be connected to create a geographically distributed MANET. In this type of network, the normal self-organizing routing algorithms cannot be applied directly. One implementation is cloud relay for persistent systems.

• Military / Tactical MANET is used by military units with a focus on security, range, and integration with existing systems. Common waveforms include US Army sSRW, Harris ANW2 and HNW, Persistent Systems Wave Relay, Trellisware TSM, and Silvus Technologies Stream Caster.

• The mobile ad hoc network (MANET) is an ad hoc network, but the ad hoc network is not necessarily MANET.

In a mobile ad hoc network (MANET), mobile units can communicate directly with each other over a wireless link without a fixed wiring infrastructure.

MANET is different from wireless mobile networks which are generally made up of static wired networks. The fixed host and the base station are interconnected through a high-speed wired network, and the mobile wireless part, where the mobile unit communicates with the base station through a wireless connection.

A base station can only communicate with mobile units that move within its coverage area called a cell. Mobile units can only communicate with each other through at least one base station. The mobile unit is powered by a battery, while the base station is powered by a stable power supply system of the static network.

In MANET, as long as the mobile unit is within its communication coverage, each mobile unit can move freely and directly communicate with another mobile unit.

The design of power-saving routing protocols for mobile ad hoc networks is necessary for universal acceptance of portable ad hoc network devices. We are targeting networks that are concerned about power consumption but still require a reasonable level of performance. Naive attempts to minimize the network to reduce power usage can cause the network to perform poorly on performance indicators. For the target network, a compromise must be found between good performance and power usage. Finding a balance between these two competing factors is not easy. We introduce a joint energy performance index that combines these two parameters, and use this index to evaluate routing protocols in self-organizing mobile networks. Most of the work in self-organizing networks is focused on improving routing attributes and routing efficiency. However, recent work has addressed the power constraints that limit the performance of routing protocols. Therefore, suitable indicators have been discussed that take into account the consumed and remaining battery power. Other tasks, such as solving energy-saving routing, minimizing power consumption, and maximizing network life. However, the purpose of this article is not to mimic previous work and attempt to build a new routing protocol to encapsulate all required attributes, but rather to be able to develop a classification mechanism so that existing and accepted protocols can be evaluated based on of its energy efficiency. In addition, we are trying to provide an indicator that we hope can be used to assess how the new agreement compares to the established agreement.

Mobile Ad Hoc Network (MANET) is a collection of autonomous nodes or terminals that communicate forming a multi-hop radio network and maintaining decentralized connectivity. Nodes can move and your network topology can be temporary. Each node acts as a client, server, and router. In such a network, there is no centralized management. Each node can join or leave the network at any time.

Routing protocols in this type of network can be divided into three main categories:

• Active routing protocols: They are based on the same principles as the routing of wired networks. The route on this route is pre-calculated. Each node maintains multiple routing tables by exchanging control packets between neighbors. In fact, if a node wants to communicate with each other, it has the ability to look at the local routing table and create the routes it needs. OLSR (Optimized Link State Routing) and FSR (Fisheye State Routing) are examples of active routing protocols.

• Reactive routing protocol: Unlike active protocols, reactive protocols calculate routes on demand. If the source node needs to send a message to the target node, it will send a request to all members of the network. After receiving the request, the destination node sends a response to the source node. However, because the investigation path may reduce application performance, routing applications are slower. The disadvantage of this protocol is that it is very expensive in terms of power and data packet transmission when determining the route, but its advantage is that it does not have to store unused information in the routing table. AODV is an example of the reactive protocol described below.

• Hybrid routing protocol: Hybrid or "hybrid" routing protocol combines the first two types of routing (active and passive). The active protocol is applied to a small area around the source (a limited number of neighbors), while the reactive protocol is applied to an area beyond this range (a remote neighbor). This combination is done to take advantage of each method and overcome its limitations. ZRP (Regional Routing Protocol) and CBRP (Cluster-Based Routing Protocol) are two important examples of hybrid protocols. One of the main and most critical factors in the ad hoc network is the limited battery power. A lot of work is focused on this configuration to reduce battery consumption. Exchanging unnecessary control messages on a regular basis to improve reliability may cause energy waste.

AODV (Ad hoc On Demand Distance Vector Routing Protocol) is a reactive routing protocol designed by Charles E. Perkins and Elizabeth M. Royer. The protocol uses four types of control messages to send data packets. The first type is the HELLO message. This type of news is exchanged regularly to maintain a neighborhood base. RREQ, RREP, and RRER are used to establish a route to the destination when any node wants to send data. The number of this control package has an obvious resource wasting effect.

To overcome the power consumption problem in this protocol, we designed a new solution that can reduce the number of HELLO messages exchanged and include power consumption factors that are useful for routing messages later. First, we try to minimize the number of greeting message exchanges. Second, we replace the regular sending time of the greeting message with another time proportional to the energy stored in the node's battery. The node receiver of this greeting message performs the opposite action to extract information proportional to the energy of the node sender and the same information contained in the greeting message.

Inserting this parameter will not affect the operation or the information contained in the exchanged message, and then we can obtain new information, which we can use to select routing.

Mobile phone and Network

All mobile operations rely on power. If we want to do more operations, energy conservation is the most important issue in wireless mobile computing due to the power limitation of mobile units. We often argue with friends about energy consumption. Power consumption is an important issue in mobile ad hoc networks.

Today, human life is completely dependent on mobile devices. Therefore, power consumption is very important in ad hoc mobile networks.

 

Mobile:

Mobile is a device that can be moved from one place to another. Mobile devices are wireless devices and they are very useful for many tasks.

Mobile phone (also known as a cell phone, cell phone, hand phone, or telephone for short) is a phone that can make and receive calls over a radio link while moving over a wide geographic area. To do this, it connects to the cellular network provided by the mobile device, which allows access to the public telephone network. In contrast, cordless phones are only used within a short distance of a single dedicated base station.

In addition to phones, modern mobile phones also support a variety of other services, such as SMS, MMS, email, Internet access, short-range wireless communication (infrared, Bluetooth), business applications, games, and photography. Mobile phones that provide these and other more general computing capabilities are called smart phones.

The first portable mobile phone was demonstrated in 1973 by Motorola's John F. Mitchell and Dr. Martin Cooper using a mobile phone weighing approximately 4.4 pounds (2 kg). In 1983, DynaTAC 8000x took the lead in the market. From 1983 to 2014, global mobile phone users increased from zero to more than 7 billion, penetrated 100% of the world's population, and reached the bottom of the economic pyramid. In 2014, the main mobile phone manufacturers were Samsung, Nokia, Apple and LG.

 

History:

Handheld cordless mobile phones are an ancient dream in radio engineering. One of the earliest descriptions can be found in Robert Heinlein's 1948 science fiction novel "Space Cadet." The protagonist has just left for Colorado from his home in Iowa, and the phone in his pocket receives a call from his father. Before heading to Earth orbit, he decided to send the phone home, "because it is so short that it can only reach the relay office on earth." Ten years later, Arthur C. Clark (Arthur C. Clarke) An Clarke's article envisions a "personal, small and compact transceiver, and everyone can carry one." Clark wrote: "We can call anyone anywhere on the planet by dialing a number." In Clark's vision, such devices will also include means of global positioning so that "no one gets lost again." Later, in the "Overview of the Future," he predicted that this device would appear in the mid-1980s. The early predecessors to the cell phone included analog radio communications from ships and trains. The race to manufacture true portable telephone equipment began after World War II and many countries are developing it. The progress of mobile phones can be traced back to early "0G" (generation zero) services, such as the Bell System mobile phone service and the enhanced mobile phone service of its successors. These "0G" systems are not cellular systems, they support few simultaneous calls and are very expensive.

Motorola demonstrated its first handheld mobile phone in 1973. NTT launched the first commercial automated cellular network in Japan in 1979. In 1981, the Nordic Mobile Telephone (NMT) system was subsequently launched simultaneously in Denmark, Finland, Norway, and Sweden. Several other countries followed suit in the early and mid-1980s. These first generation ("1G") systems can support more simultaneous calls, but still use analog technology.

In 1991, Radiolinja launched second generation (2G) digital cellular technology based on the GSM standard in Finland, sparking competition in the industry as new operators challenged existing 1G network operators.

Ten years later, in 2001, NTT Do Como launched the third generation (3G) of the WCDMA standard in Japan. It is closely followed by the 3.5G, 3G + or Turbo 3G enhancements based on the High Speed ​​Packet Access (HSPA) series, which allow the UMTS network to have higher speed and data transmission capacity. From 2001 to 2009, it is clear that at some point, 3G networks will be overwhelmed by the growth of bandwidth intensive applications such as streaming media. Therefore, the industry has started looking for data-optimized fourth-generation technology, which is expected to increase the speed to 10 times that of existing 3G technology. The first two commercial technologies known as 4G are the WiMAX standard (provided by Sprint in the US) and the LTE standard, initially provided by TeliaSonera in Scandinavia. 

 

Features of Mobile Phones:

All mobile phones have many common features, but manufacturers are also trying to implement additional features to differentiate their products and make them more attractive to consumers. This has led to great innovations in mobile phone development over the past 20 years. Common components on all phones are:

• Battery, which provides power for phone functions.

• An input mechanism that allows users to interact with the phone. The most common input mechanism is the keyboard, but touchscreens can also be found on most smartphones.

• In response to user input on the screen, display text messages, contacts, and more.

• A basic mobile phone service that allows users to make calls and send text messages.

• All GSM mobile phones use SIM cards to allow the exchange of accounts between devices. Some CDMA devices also have similar cards called UIM.

• Individual GSM, WCDMA, iDEN devices and certain satellite phones are uniquely identified by International Mobile Equipment Identity (IMEI) numbers.

Low-end phones are usually called feature phones and provide basic phone functions. Mobile phones that have more advanced computing capabilities through the use of native software applications are called smart phones.

However, in terms of sound quality, smartphones and feature phones are very limited. Some functions that can improve audio quality, such as LTE voice and high-definition voice, have appeared, and are usually available on newer smartphones. Sound quality is still a problem for both of you, because it depends not so much on the phone itself as on the quality of the network, in case a long time passes and a bottleneck/blocking point is found on the way. Therefore, in long distance calls, even LTE voice, high definition voice and other functions may not improve the situation. In some cases, smartphones can even improve the audio quality of long distance calls by using VoIP phone services and other people's WiFi / Internet connections. Launched several series of phones to address specific market segments, such as RIM BlackBerry that focuses on the email needs of corporate / corporate customers; Sony Ericsson `Walkman` series mobile phones / music and` Cyber ​​shot` series mobile phones / cameras; Nokia N series, Palm Pre, HTC Dream and Apple iPhone multimedia phones.

 

Using Mobile Phones:

Mobile phones have many uses, such as keeping in touch with family members, conducting business, and using the phone in emergency situations. Some people carry more than one mobile phone for different purposes, such as business and personal use. You can also use multiple SIM cards to take advantage of the different calling plans; specific plans may offer cheaper local calls, long distance calls, international calls, or roaming. Mobile phones are also used in various social settings, such as:

• A Motorola study found that one in ten mobile phone users owns a second phone, and that phone is generally kept secret from other family members. These phones can be used for activities such as extramarital affairs or secret business transactions.

• Some organizations assist victims of domestic violence by providing mobile phones for use in emergency situations. These are usually refurbished phones.

• The appearance of text messages gave rise to mobile novels. The first literary genre to appear in the honeycomb age, the first to be sent by SMS to a website that collects complete novels.

• Mobile phones also promote activism and public journalism that Reuters and Yahoo are exploring. And small independent news companies, like Sri Lanka's Jasmine News.

• The United Nations reports that mobile phones are spreading faster than any other technology and can improve the lives of the poorest people in developing countries by providing access to information where there are no landlines or the Internet, especially in least developed countries. Country: The use of mobile phones has also led to a large number of micro-enterprises by providing jobs, such as selling airtime on the street and repairing or refurbishing mobile phones.

• In Mali and other African countries, people used to travel from village to village to inform their family and friends about weddings, births and other events. These activities are now avoided within mobile phone coverage, which is usually better than landline coverage. The coverage is greater.

• The television industry has recently started using mobile phones to promote live television viewing through mobile applications, advertising, social television, and mobile television. 86% of Americans use cell phones while watching television.

• Mobile phone sharing is common in some parts of the world. It is common in Indian cities because groups of family and friends often share one or more mobile phones among their members. There are obvious economic benefits, but generally family customs and traditional gender roles also play a role. Usually a village only uses a mobile phone, which may be owned by a teacher or missionary, but all members of the village can make the necessary calls. 

 

Ad hoc:

Ad hoc means temporary. An ad hoc network is a group of wireless mobile computers (or nodes) in which each node cooperates by forwarding data packets to each other to allow the nodes to communicate outside the direct wireless transmission range.

 

Network:

A computer network or data network is a telecommunications network that allows computers to exchange data. In computer networks, networked computing devices transfer data to each other over data connections (network links). The data is transmitted in the form of data packets. The connection between the nodes is established by wired means or wireless means. The most famous computer network is the Internet.

The network computing equipment that initiates, routes, and terminates data is called a network node. Nodes can include hosts such as people, phones, servers, and network hardware. When a device can exchange information with another device, regardless of whether they are directly connected to each other, it can be said that two of these devices are networked. The computer network differs in the transmission medium used to carry its signals, the communication protocol used to organize network traffic, network scale, topology, and organizational intent. In most cases, communication protocols overlap (i.e. they use) other more specific or general communication protocols, except for the physical layer that directly deals with the transmission medium.

Computer network support applications, such as access to the World Wide Web, shared servers, printers and fax machines, and use of e-mail and instant messaging applications. A network is a group of two or more interconnected computer systems. There are many types of computer networks, including:

• Local Area Network (LAN)-Computers are geographically close together (that is, in the same building).

• Wide Area Network (WAN)- Computers are further separated and connected by telephone lines or radio waves.

• Camp Network (CAN)-Computers are located in a limited geographic area, such as a campus or military base.

• Metropolitan Area Network (MAN)-A data network designed for towns or cities.

• Home Area Network (HAN) - A network contained in a user's home, used to connect personal digital devices.