wifi
TABLE OF CONTENTS
1)INTRODUCTION 2
3) 2
4)CONTENTS 2
History 2
Uses 3
Advantages and challenges 4
Operational advantages 4
Limitations 5
Reach 5
Mobility 6
Threats to security 6
Population 6
Channel pollution 7
5)CONCLUSION 7
6)REFERENCE 7
INTRODUCTION
Wi-Fi (pronounced /ˈwaɪfaɪ/) is a trademark of the Wi-Fi Alliance for certified products based on the IEEE 802.11 standards. This certification warrants interoperability between different wireless devices.
The term Wi-Fi is often used by the public as a synonym for wireless LAN (WLAN); but not every wireless LAN product has a Wi-Fi certification, which may be because of certification costs that must be paid for each certified device type.
CONTENTS
History
Wi-Fi uses both single carrier direct-sequence spread spectrum radio technology (part of the larger family of spread spectrum systems) and multi-carrier OFDM (Orthogonal Frequency Division Multiplexing) radio technology. The regulations for unlicensed spread spectrum enabled the development of Wi-Fi, its onetime competitor HomeRF, Bluetooth, and many other products such as some types of cordless telephones.
Unlicensed spread spectrum was first made available in the US by the Federal Communications Commission in 1985 and these FCC regulations were later copied with some changes in many other countries enabling use of this technology in all major countries.The FCC action was proposed by Michael Marcus of the FCC staff in 1980 and the subsequent regatory action took 5 more years. It was part of a broader proposal to allow civil use of spread spectrum technology and was opposed at the time by main stream equipment manufacturers and many radio system operators.
The precursor to Wi-Fi was invented in 1991 by NCR Corporation/AT&T (later Lucent & Agere Systems) in Nieuwegein, the Netherlands. It was initially intended for cashier systems; the first wireless products were brought on the market under the name WaveLAN with speeds of 1 Mbit/s to 2 Mbit/s. Vic Hayes, who held the chair of IEEE 802.11 for 10 years and has been named the 'father of Wi-Fi,' was involved in designing standards such as IEEE 802.11b, and 802.11a.
The original patents behind 802.11 Wi-Fi technology, filed in 1996, are held by the CSIRO, an Australian research body. The patents have been the subject of protracted and ongoing legal battles between the CSIRO and major IT corporations over the non-payment of royalties. In 2009 the CSIRO reached a settlement with 14 companies, including Hewlett-Packard, Intel, Dell, Toshiba, ASUS,
Microsoft and Nintendo, on the condition that the CSIRO did not broadcast the resolution
Uses
A roof mounted Wi-Fi antenna
A Wi-Fi antenna
A Wi-Fi enabled device such as a PC, game console, mobile phone, MP3 player or PDA can connect to the Internet when within range of a wireless network connected to the Internet. The coverage of one or more interconnected access points — called a hotspot— can comprise an area as small as a single room with wireless-opaque walls or as large as many square miles covered by overlapping access points. Wi-Fi technology has served to set up mesh networks, for example, in London. Both architectures can operate in community networks.i-Fi can make access publicly available at businesses provided either free of charge or to subs
In addition to restricted use in homes and offices, Wcribers to various providers. Organizations and such as airports, hotels and restaurants often provide free hotspots to attract or assist clients. Czech RepublicEnthusiasts or authorities who wish to provide services or even to promote business in a given area sometimes provide free Wi-Fi access. There are already[update] more than 300 metropolitan-wide Wi-Fi (Muni-Fi) projects in progress. There were 879 Wi-Fi based Wireless Internet service providers in the as of May 2008.
Wi-Fi also allows connectivity in peer-to-peer (wireless ad-hoc network) mode, which enables devices to connect directly with each other. This connectivity mode can prove useful in consumer electronics and gaming applications.
When wireless networking technology first entered the market many problems ensued for consumers who could not rely on products from different vendors working together. The Wi-Fi Alliance began as a community to solve this issue — aiming to address the needs of the end-user and to allow the technology to mature. The Alliance created the branding Wi-Fi CERTIFIED to reassure consumers that products will interoperate with other products displaying the same branding.
Many consumer devices use Wi-Fi. Amongst others, personal computers can network to each other and connect to the Internet, mobile computers can connect to the Internet from any Wi-Fi hotspot, and digital cameras can transfer images wirelessly.
Routers which incorporate a DSL-modem or a cable-modem and a Wi-Fi access point, often set up in homes and other premises, provide Internet-access and internetworking to all devices connected (wirelessly or by cable) to them. One can also connect Wi-Fi devices in ad-hoc mode for client-to-client connections without a router. Wi-Fi also enables places which would traditionally not have network to be connected, for example bathrooms, kitchens and garden sheds. The "father of Wi-Fi", Vic Hayes, stated that being able to access the internet whilst answering a call of nature was "one of life's most liberating experiences".
As of 2007 Wi-Fi technology had spread widely within business and industrial sites. In business environments, just like other environments, increasing the number of Wi-Fi access-points provides redundancy, support for fast roaming and increased overall network-capacity by using more channels or by defining smaller cells. Wi-Fi enables wireless voice-applications (VoWLAN or WVOIP). Over the years, Wi-Fi implementations have moved toward "thin" access-points, with more of the network intelligence housed in a centralized network appliance, relegating individual access-points to the role of mere "dumb" radios. Outdoor applications may utilize true mesh topologies. As of 2007 Wi-Fi installations can provide a secure computer networking gateway, firewall, DHCP server, intrusion detection system, and other functions
Advantages and challenges
A keychain size Wi-Fi detector.
Operational advantages
Wi-Fi allows local area networks (LANs) to be deployed without wires for client devices, typically reducing the costs of network deployment and expansion. Spaces where cables cannot be run, such as outdoor areas and historical buildings, can host wireless LANs.
Wireless network adapters are now built into most laptops. The price of chipsets for Wi-Fi continues to drop, making it an economical networking option included in even more devices. Wi-Fi has become widespread in corporate infrastructures.
Different competitive brands of access points and client network interfaces are inter-operable at a basic level of service. Products designated as "Wi-Fi Certified" by the Wi-Fi Alliance are backwards compatible. Wi-Fi is a global set of standards. Unlike mobile telephones, any standard Wi-Fi device will work anywhere in the world.
Wi-Fi is widely available in more than 220,000 public hotspots and tens of millions of homes and corporate and university campi worldwide. The current version of Wi-Fi Protected Access encryption (WPA2) is not easily defeated, provided strong passwords are used. New protocols for Quality of Service (WMM) make Wi-Fi more suitable for latency-sensitive applications (such as voice and video), and power saving mechanisms (WMM Power Save) improve battery operation.
Air Canada has already announced its plans for providing in-flight Wi-Fi services for its customers.
Limitations
Spectrum assignments and operational limitations are not consistent worldwide. Most of Europe allows for an additional 2 channels beyond those permitted in the U.S. for the 2.4 GHz band. (1–13 vs. 1–11); Japan has one more on top of that (1–14). Europe, as of 2007, was essentially homogeneous in this respect. A very confusing aspect is the fact that a Wi-Fi signal actually occupies five channels in the 2.4 GHz band resulting in only three non-overlapped channels in the U.S.: 1, 6, 11, and three or four in Europe: 1, 5, 9, 13 can be used if all the equipment on a specific area can be guaranteed not to use 802.11b at all, even as fallback or beacon. Equivalent isotropically radiated power (EIRP) in the EU is limited to 20 dBm (100 mW).
Reach
Large satellite dish specially made for long-range Wi-Fi connection in Venezuela
Wi-Fi networks have limited range. A typical Wi-Fi home router using 802.11b or 802.11g with a stock antenna might have a range of 32 m (120 ft) indoors and 95 m (300 ft) outdoors. The new IEEE 802.11n however, can exceed that range by more than double.[citation needed] Range also varies with frequency band. Wi-Fi in the 2.4 GHz frequency block has slightly better range than Wi-Fi in the 5 GHz frequency block. Outdoor range with improved (directional) antennas can be several kilometres or more with line-of-sight. In general, the maximum amount of power that a Wi-Fi device can transmit is limited by local regulations, such as FCC Part 15 in USA.
Wi-Fi performance decreases roughly quadratically as distance increases at constant radiation levels.
Due to reach requirements for wireless LAN apBluetoothplications, power consumption is fairly high compared to some other standards. Technologies such as , which are designed to support wireless PAN applications, provide a much shorter propagation range of <10m (ref. e.g. IEEE Std. 802.15.4 section 1.2 scope) and so in general have a lower power consumption. Other low-power technologies such as Zigbee have fairly long range, but much lower data rate. The high power consumption of Wi-Fi makes battery life a concern for mobile devices.
A number of "no new wires" technologies have been developed to provide alternatives to Wi-Fi for applications in which Wi-Fi's indoor range is not adequate and where installing new wires (such as CAT-5) is not possible or cost-effective. One example is the ITU-T G.hn standard for high speed Local area networks using existing home wiring (coaxial cables, phone lines and power lines). Although G.hn does not provide some of the advantages of Wi-Fi (such as mobility or outdoor use), it's designed for applications (such as IPTV distribution) where indoor range is more important than mobility.
Due to the complex nature of Radio propagation at typical Wi-Fi frequencies, particularly the effects of signal reflection off of trees and buildings, Wi-Fi signal strength can only be predicted generally for any given area in relation to a transmitter. ] This effect does not apply equally to long-range Wi-Fi, since longer links typically operate from towers that broadcast above the surrounding foliage.
Mobility
Speed vs. Mobility of wireless systems: Wi-Fi, HSPA, UMTS, GSM
Because of the very limited practical range of Wi-Fi, mobile use is essentially confined to such applications as inventory taking machines in warehouses or retail spaces, barcode reading devices at check-out stands or receiving / shipping stations. Mobile use of Wi-Fi over wider ranges is limited to move, use, move, as for instance in an automobile moving from one hotspot to another (Wardriving). Other wireless technologies are more suitable as illustrated in the graphic.
Threats to security
The most common wireless encryption standard, Wired Equivalent Privacy or WEP, has been shown to be easily breakable even when correctly configured. Wi-Fi Protected AccessN (WPA and WPA2), which began shipping in 2003, aims to solve this problem and is now available on most products. Wi-Fi Access Points typically default to an "open" (encryption-free) mode. Novice users benefit from a zero-configuration device that works out of the box, but this default is without any wireless security enabled, providing open wireless access to their LAN. To turn security on requires the user to configure the device, usually via a software graphical user interface (GUI). Wi-Fi networks that are open (unencrypted) can be monitored and used to read and copy data (including personal information) transmitted over the network, unless another security method is used to secure the data, such as a VPN or a secure web page. (See HTTPS/Secure Socket Layer.)
Population
Many 2.4 GHz 802.11b and 802.11g access points default to the same channel on initial startup, contributing to congestion on certain channels. To change the channel of operation for an access point requires the user to configure the device.
Channel pollution
For more details on this topic, see Electromagnetic interference at 2.4 GHz.
Standardization is a process driven by market forces. Interoperability issues between non-Wi-Fi brands or proprietary deviations from the standard can still disrupt connections or lower throughput speeds on all user's devices that are within range, to include the non-Wi-Fi or proprietary product. Moreover, the usage of the ISM band in the 2.45 GHz range is also common to Bluetooth, WPAN-CSS, ZigBee and any new system will take its share.
Wi-Fi pollution, or an excessive number of access points in the area, especially on the same or neighboring channel, can prevent access and interfere with the use of other access points by others, caused by overlapping channels in the 802.11g/b spectrum, as well as with decreased signal-to-noise ratio (SNR) between access points. This can be a problem in high-density areas, such as large apartment complexes or office buildings with many Wi-Fi access points. Additionally, other devices use the 2.4 GHz band: microwave ovens, security cameras, Bluetooth devices and (in some countries) Amateur radio, video senders, cordless phones and baby monitors, all of which can cause significant additional interference. General guidance to those who suffer these forms of interference or network crowding is to migrate to a Wi-Fi 5 GHz product, (802.11a, or the newer 802.11n if it has 5 GHz support) because the 5 GHz band is relatively unused, and there are many more channels available. This also requires users to set up the 5 GHz band to be the preferred network in the client and to configure each network band to a different name (SSID). It is also an issue when municipalities, or other large entities such as universities, seek to provide large area coverage. This openness is also important to the success and widespread use of 2.4 GHz Wi-Fi
CONCLUSION
The Alliance promotes standards with the aim of improving the interoperability of wireless local area network products based on the IEEE 802.11 standards. The Wi-Fi Alliance, a consortium of separate and independent companies, agrees on a set of common interoperable products based on the family of IEEE 802.11 standards. The Wi-Fi Alliance certifies products via a set of defined test-procedures to establish interoperability. Those manufacturers with membership of Wi-Fi Alliance and whose products pass these interoperability tests can mark their products and product packaging with the Wi-Fi logo
6) REFERENCES
Wi-Fi wikipedia the free encyclopedia
"Basic Facts About Wi-Fi and its Advancement "The Genesis of Unlicensed Wireless Policy
Table of Contents
Contents
[hide]
1 Types
2 Community and cataloging
3 Popularity
INTRODUCTION
A blog (a contraction of the term weblog) is a type of website, usually maintained by an individual with regular entries of commentary, descriptions of events, or other material such as graphics or video. Entries are commonly displayed in reverse-chronological order. "Blog" can also be used as a verb, meaning to maintain or add content to a blog.
Many blogs provide commentary or news on a particular subject; others function as more personal online diaries. A typical blog combines text, images, and links to other blogs, Web pages, and other media related to its topic. The ability for readers to leave comments in an interactive format is an important part of many blogs. Most blogs are primarily textual, although some focus on art (artlog), photographs (photoblog), sketches (sketchblog), videos (vlog), music (MP3 blog), and audio (podcasting). Micro-blogging is another type of blogging, featuring very short posts.
CONTENTS
Types
There are many different types of blogs, differing not only in the type of content, but also in the way that content is delivered or written.
Personal blogs
The personal blog, an ongoing diary or commentary by an individual, is the traditional, most common blog. Personal bloggers usually take pride in their blog posts, even if their blog is never read by anyone but them. Blogs often become more than a way to just communicate; they become a way to reflect on life or works of art. Blogging can have a sentimental quality. Few personal blogs rise to fame and the mainstream, but some personal blogs quickly garner an extensive following. A type of personal blog is referred to as "microblogging," which is extremely detailed blogging as it seeks to capture a moment in time. Sites, such as Twitter, allow bloggers to share thoughts and feelings instantaneously with friends and family and is much faster than e-mailing or writing. This form of social media lends to an online generation already too busy to keep in touch.[2]
Corporate blogs
A blog can be private, as in most cases, or it can be for business purposes. Blogs, either used internally to enhance the communication and culture in a corporation or externally for marketing, branding or public relations purposes are called corporate blogs.
By genre
Some blogs focus on a particular subject, such as political blogs, travel blogs, house blogs,[3][4] fashion blogs, project blogs, education blogs, niche blogs, classical music blogs, quizzing blogs and legal blogs (often referred to as a blawgs) or dreamlogs. Two common types of genre blogs are art blogs and music blogs. A blog feaurting discussions especially about home and family is not uncommonly called a mom blog.[5][6][7][8][9] While not a legitimate type of blog, one used for the sole purpose of spamming is known as a Splog.
By media type
A blog comprising videos is called a vlog, one comprising links is called a linklog, a site containing a portfolio of sketches is called a sketchblog or one comprising photos is called a photoblog.[10] Blogs with shorter posts and mixed media types are called tumblelogs. Blogs that are written on typewriters and then scanned are called typecast or typecast blogs; see typecasting (blogging).
A rare type of blog hosted on the Gopher Protocol is known as a Phlog.
By device
Blogs can also be defined by which type of device is used to compose it. A blog written by a mobile device like a mobile phone or PDA could be called a moblog.[11] One early blog was Wearable Wireless Webcam, an online shared diary of a person's personal life combining text, video, and pictures transmitted live from a wearable computer and EyeTap device to a web site. This practice of semi-automated blogging with live video together with text was referred to as sousveillance. Such journals have been used as evidence in legal matters.[citation needed]
Community and cataloging
The Blogosphere
The collective community of all blogs is known as the blogosphere. Since all blogs are on the internet by definition, they may be seen as interconnected and socially networked, through blogrolls, comments, linkbacks (refbacks, trackbacks or pingbacks) and backlinks. Discussions "in the blogosphere" have been used by the media as a gauge of public opinion on various issues. A collection of local blogs is sometimes referred to as a bloghood.[12]
Blog search engines
Several blog search engines are used to search blog contents, such as Bloglines, BlogScope, and Technorati. Technorati, which is among the most popular blog search engines, provides current information on both popular searches and tags used to categorize blog postings[13]. The research community is working on going beyond simple keyword search, by inventing new ways to navigate through huge amounts of information present in the blogosphere, as demonstrated by projects like BlogScope.[citation needed]
Blogging communities and directories
Several online communities exist that connect people to blogs and bloggers to other bloggers, including BlogCatalog and MyBlogLog[14].
Blogging and advertising
It is common for blogs to feature advertisements either to financially benefit the blogger or to promote the blogger's favorite causes. The popularity of blogs has also given rise to "fake blogs" in which a company will create a fictional blog as a marketing tool to promote a product.[15]
Popularity
Researchers have analyzed the dynamics of how blogs become popular. There are essentially two measures of this: popularity through citations, as well as popularity through affiliation (i.e. blogroll). The basic conclusion from studies of the structure of blogs is that while it takes time for a blog to become popular through blogrolls, permalinks can boost popularity more quickly, and are perhaps more indicative of popularity and authority than blogrolls, since they denote that people are actually reading the blog's content and deem it valuable or noteworthy in specific cases.[16]
The blogdex project was launched by researchers in the MIT Media Lab to crawl the Web and gather data from thousands of blogs in order to investigate their social properties. It gathered this information for over 4 years, and autonomously tracked the most contagious information spreading in the blog community, ranking it by recency and popularity. It can therefore be considered the first instantiation of a memetracker. The project is no longer active, but a similar function is now served by tailrank.com.
Blogs are given rankings by Technorati based on the number of incoming links and Alexa Internet based on the Web hits of Alexa Toolbar users. In August 2006, Technorati found that the most linked-to blog on the internet was that of Chinese actress Xu Jinglei.[17] Chinese media Xinhua reported that this blog received more than 50 million
CONCLUSION
REFERENCE
^ "Welcome to Technorati". unknown. http://technorati.com/about/. Retrieved on 2008-06-05.
^ Wong, Wailin (2008-07-01). ""I'm now reading a story on microblogs"". Chicago Tribune. http://www.chicagotribune.com/business/chi-tue-microblogging-jul01,0,3597900.story. Retrieved on 2008-07-01.
^ Stephan Metcalf, "Fixing a Hole", New York Times, March 2006
^ Jennifer Saranow, "Blogwatch: This Old House", Wall Street Journal, September 2007
^ http://www.time.com/time/magazine/article/0,9171,993832-3,00.html
^ http://www.post-gazette.com/pg/07304/829747-51.stm
^ http://www.independent.co.uk/news/science/the-drooling-minutiae-of-childhood-revealed-for-all-to-see-as-mommy-blogs-come-of-age-485573.html
^ http://www.omaha.com/index.php?u_page=1219&u_sid=10322842
^ http://www.nytimes.com/2008/07/27/fashion/27blogher.html?_r=2&sq=blogher%20women%20blogging&st=cse&adxnnl=1&scp=1&adxnnlx=1228493929-MAKTyKJ3qiW/+fidCwXbFg
^ "What is a photoblog". Photoblogs.org Wiki. http://wiki.photoblogs.org/wiki/What_is_a_Photoblog. Retrieved on 2006-06-25.
^ "Blogging goes mobile". BBC News. 2003-02-23. http://news.bbc.co.uk/1/hi/technology/2783951.stm. Retrieved on 2008-06-05.
^ DailyPundit
^ "Welcome to Technorati". unknown. http://technorati.com/about. Retrieved on 2008-06-25.
^ name="MyBlogLog">"About MyBlogLog". MyBlogLog. http://www.mybloglog.com/buzz/help/#a200502282152271. Retrieved on 2007-06-29.
^ Gogoi, Pallavi (2006-10-09). "Wal-Mart's Jim and Laura: The Real Story". BusinessWeek. http://www.businessweek.com/bwdaily/dnflash/content/oct2006/db20061009_579137.htm. Retrieved on 2008-08-06.
^ Marlow, C. Audience, structure and authority in the weblog community. Presented at the International Communication Association Conference, May, 2004, New Orleans, LA.
^ a b Fickling, David, Internet killed the TV star, The Guardian NewsBlog, 15 August 2006
^ "Xu Jinglei most popular blogger in world". China Daily. 2006-08-24. http://www.chinadaily.com.cn/china/2006-08/24/content_672747.htm. Retrieved on 2008-06-05.
^ "blogging Bonnie.". Poynter.org. 2003-09-18. http://www.poynter.org/column.asp?id=52&aid=48413/.
^ "Blooker rewards books from blogs". BBC News. 2005-10-11. http://news.bbc.co.uk/2/hi/technology/4326908.stm. Retrieved on 2008-06-05.
^ "Blooker prize honours best blogs". BBC News. 2007-03-17. http://news.bbc.co.uk/2/hi/technology/6446271.stm. Retrieved on 2008-06-05.
^ Dude, here's my book
^ McQueen MP. (2009). Bloggers, Beware: What You Write Can Get You Sued. WSJ.
^ Doe v. Cahill, 884 A.2d 451 (Del. 2005).
^ "New Straits Times staffers sue two bloggers". Reporters Without Borders. 2007-01-19. http://www.rsf.org/article.php3?id_article=20489. Retrieved on 2008-06-05.
^ "Government plans to force bloggers to register". Reporters Without Borders. 2007-04-06. http://www.rsf.org/article.php3?id_article=21606. Retrieved on 2008-06-05.
^ Kesmodel, David (2005-08-31). Wall Street Journal "Blogger Faces Lawsuit Over Comments Posted by Readers". Wall Street Journal Online. http://online.wsj.com/public/article/SB112541909221726743-_vX2YpePQV7AOIl2Jeebz4FAfS4_20060831.html?mod=blogs Wall Street Journal. Retrieved on 2008-06-05.
^ Wired Magazine, Legal Showdown in Search Fracas, Sept 8, 2005
^ Slashdot, Aug 31
^ SearchEngineWatch
^ Interview With Aaron Wall/
^ Aaron Wall on Local Search /
^ Aaron Wall's SEO Book Blog
^ Sanderson, Cathrine (2007-04-02). "Blogger beware!". Guardian Unlimited. http://commentisfree.guardian.co.uk/catherine_sanderson/2007/04/blogger_beware.html. Retrieved on 2007-04-02.
^ Twist, Jo (2004-11-03). "US Blogger Fired by her Airline". BBC News. http://news.bbc.co.uk/1/hi/technology/3974081.stm. Retrieved on 2008-06-05.
^ "Delta employee fired for blogging sues airline". USA Today. 2005-09-08. http://www.usatoday.com/travel/news/2005-09-08-delta-blog_x.htm. Retrieved on 2008-06-05.
^ "Queen of the Sky gets marching orders". The Register. 2004-11-03. http://www.theregister.co.uk/2004/11/03/airline_blogger_sacked/. Retrieved on 2008-06-05.
^ "Lecturer's Blog Sparks Free Speech Row". The Guardian. 2006-05-03. http://education.guardian.co.uk/higher/news/story/0,,1766663,00.html. Retrieved on 2008-06-05. See also Forget the Footnotes
^ "NBA fines Cuban $200K for antics on, off court". ESPN. 2006-05-11. http://sports.espn.go.com/nba/playoffs2006/news/story?id=2440355. Retrieved on 2008-06-05.
^ Hansen, Evan (2005-02-08). "Google blogger has left the building". CNET News. http://news.cnet.com/Google-blogger-has-left-the-building/2100-1038_3-5567863.html. Retrieved on 2007-04-04.
^ "Official Story, straight from the source". http://blog.plaxoed.com/2005/02/11/the-official-story-straight-from-the-source/.
^ http://cities.expressindia.com/fullstory.php?newsid=152721
^ "The Hill's Sex Diarist Reveals All (Well, Some)". The Washington Post. 2004-05-23. http://www.washingtonpost.com/wp-dyn/articles/A48909-2004May22.html. Retrieved on 2008-06-05.
^ "Steamy D.C. Sex Blog Scandal Heads to Court". The Associated Press ,MSNBC. 2006-12-27. http://www.msnbc.msn.com/id/16366256/. Retrieved on 2008-06-05.
^ "Bridget Jones Blogger Fire Fury". CNN. 2006-07-19. http://edition.cnn.com/2006/WORLD/europe/07/19/france.blog/index.html?section=cnn_tech. Retrieved on 2008-06-05.
^ "Sacked "petite anglaise" blogger wins compensat
CARA SOLAT ISTIKARAH
Cara Solat Istikhoroh
Solat Istikhoroh dilakukan seperti solat sunnah yang lain iaitu sebanyak dua rakaat, sama ada siang atau malam hari (selama sedang memerlukan petunjuk), dalam setiap rakaatnya membaca al-Fatihah dan surah apa saja yang sudah dihafal, lalu mengangkat tangan sambil berdoa dengan doa istikhoroh yang diajarkan oleh Nabi seperti yang telah disebutkan/dibentangkan di atas (dalam hadis Bukhori dari jalan Jabir Bin Abdulloh). (Asal perkataan ini oleh Ibnu Baz dalam Majmu’ Fatawa wa Maqolat Mutanawwi’ah, 11/421)
Adakah Dalam Solat Istikhoroh Ada Bacaan Khusus/Tertentu?
Imam Nawawi mengatakan: “Disunnahkan pada raka’at pertama setelah al-Fatihah membaca surat al-Kafirun dan raka’at ke dua setelah al-Fatihah membaca surat al-Ikhlash” (al-Majmu’ Syarh al-Muhadzdzab 2/377), hal ini didasari oleh maksud orang yang beristikhoroh supaya mengikhlaskan niatnya hanya kepada Allah, sehingga yang patut dibaca adalah dua surat tersebut.
Sedangkan al-Hafiz al-’Iraqi mengatakan (Perkataan ini dinukil dari Tuhfatul Ahwadzi 2/484): “Aku tidak menjumpai satu hadis pun tentang penentuan bacaan surah-surah khusus dalam solat Istikhoroh.”
Dan keterangan di atas jelaslah bahwasanya pendapat yang lebih kuat adalah tidak adanya ketentuan surah-surah yang dibaca ketika solat Istikhoroh, lantaran tidak ada keterangan dari Rasulullah akan hal itu, dan mereka yang mensunnahkan surah-surah tertentu tidak mendatangkan dalil al-Qur’an dan Sunnah, sehingga kita katakan disunnahkan setelah membaca al-Fatihah di masing-masing raka’at untuk membaca surah apa saja dari al-Qur’an yang telah dihafal.
Berkata Ibnu Bazz (Majmu’ Fatawa wa Maqolat Mutanawzvi’ah 11/421): “Hendaknya (orang yang solat Istikhoroh) membaca al-Fatihah di setiap raka’at dan membaca surah apa saja yang mudah.”
Bilakah Doa Istikhoroh Dibacakan?
Doa Istikhoroh boleh dibaca samaada sebelum salam atau selepas salam selepas solat dua roka’at. (Sebagaimana fatwa Syaikhul Islam Ibnu Taimiyah dalam Majmu’ Fatawanya 12/105)
a. Sebelum salam
Adapun dibolehkan membaca do’a istikhoroh sebelum salam ini berdasarkan:
1. Kebanyakan doa Nabi dalam sholat dilakukan sebelum salam (setelah tasyahud akhir), seperti yang dijelaskan oleh Abu Hurairoh, beliau berkata: “Nabi bersabda: Apabila kalian selesai dari tasyahud yang terakhir, hendaklah berdo’a meminta perlindungan kepada Allah dari empat perkara, iaitu mengucapkan (maksudnya);
Ya Allah, aku berlindung kepada-Mu dari azab neraka Jahannam, dan azab kubur, dari fitnah kehidupan dan kematian, dan dari fitnah al-Masih ad-Dajjal. (Hadis Riwayat Bukhari 1377, dan Muslim 588)
2. Demikian juga Rasulullah mengajari Abu Bakar tatkala beliau minta diajarkan do’a yang boleh dibaca dalam solatnya, lalu Nabi memerintahkan beliau untuk membaca (maksudnya);
Ya Allah sesungguhnya aku telah menzalimi diriku dengan kezaliman yang banyak, tidak ada yang mengampuni dosa-dosa kecuali Engkau, maka ampunilah aku dengan ampunan dari-Mu, dan rahmatilah aku, sesungguhnya Engkaulah yang Maha Pengampun lagi Maha Penyayang. (Hadis Riwayat Bukhari 834 dan Muslim 3/7/27)
3. Dalam Hadis Jabir bin Abdullah, Rasulullah tidak menentukan tempat dibacanya doa istikharah apakah harus dibaca sebelum salam atau setelah salam.
b. Sesudah salam
Sedangkan dibolehkan doa Istikhoroh dibaca sesudah salam berdasarkan zahir hadis yang menunjukkan doa tersebut dibaca sesudah salam, sebagaimana Nabi bersabda (yang ertinya): “Apabila di antara kalian berkeinginan/bermaksud terhadap suatu perkara, hendaklah solat sunnah dua rakaat bukan termasuk wajib, kemudian berdo’a...”
Berkata Ibnu Baz: “Sholat Istikhoroh hukumnya sunnah, dan do’a istikhoroh tempatnya setelah salam sebagaimana (zahir) hadis yang telah datang dari Rasulullah” (Majmu’ Fatawa wa Maqolat Mutanawwi’ah 11/421422). (Demikian juga difatwakan oleh Lajnah Da’imah dalam Fatwa no. 10666)
Apa Yang Dilakukan Setelah Solat Istikhoroh Dan Bermusyawarah?
Imam Nawawi r.h. berkata (Perkataan Imam Nawawi (dinukil secara bebas) ini dinukil oleh Imam Syaukani dalam Nailul Author 2/298): “Setelah seseorang melakukan solat Istikhoroh, sebaiknya dia menjalani apa yang dia rasakan lapang dadanya terhadap perkara tersebut baik meneruskan maksudnya atau meninggalkannya.”
Kemudian beliau melanjutkan perkataannya:
“Bagi orang yang hendak beristikhoroh hendaklah ia menghilangkan kecondongan hatinya terhadap suatu perkara sebelum melakukan solat dan doa Istikhoroh, dan tidak selayaknya bersandar kepada adanya kecondongan hati sebelum istikhoroh, kerana apabila ada kecondongan hati sebelum istikhoroh, lalu dia melakukan istikhoroh, bererti dia tidak beristikhoroh, kerana istikhoroh dilakukan ketika bimbang dan meminta dipilihkan yang terbaik dari Allah untuknya.”
Boleh Mengulang Solat Istikhoroh Dalam Satu Perkara
Ibnu Utsaimin berkata (Dinukil secara bebas dari Syarh Riyadhus Sholihin oleh Ibnu Utsaimin 2/515): “Setelah melakukan solat dan do’a istikhoroh, apabila merasa lapang dadanya terhadap suatu perkara baik meneruskan atau meninggalkan, maka inilah yang diharapkan, tetapi apabila tetap bimbang dan tidak merasa lapang dadanya, maka dia boleh mengulangi solat dan doa Istikhorohnya ke dua kali, ke tiga kalinya, dan seterusnya, hal ini lantaran orang yang beristikhoroh adalah orang yang meminta petunjuk kepada Allah akan kebaikan yang akan dia lakukan sehingga apabila tidak jelas baginya kebaikannya atau tetap ragu maka dia boleh beristikhoroh berulang kali.”
Adakah Tanda-Tanda Dikabulkannya Permintaan?
Sebahagian orang berkata: “Setelah melakukan solat dan doa Istikhoroh, maka akan datang petunjuk dalam mimpinya, maka diambil pilihan sebagaimana mimpinya,” oleh kerana itu ada sebagian orang berwudhu’, lalu melakukan solat dan doa istikhoroh, kemudian terus tidur (mengharap petunjuk datang melalui mimpi), bahkan sebahagian mereka menyengaja memakai pakaian berwarna putih (supaya bermimpi baik), semua ini hanyalah prasangka manusia (yang tidak ada dasarnya). (Lihat Bahjah an-Nadzirin Syarh Riyadhus Sholihin oleh Syaikh Salim bin led al-Hilali 2/44)
Kesimpulan
1. Rasa bimbang, ragu, dan ketidak-tahuan baik dan buruknya suatu perkara adalah hal yang wajar, kerana semua itu termasuk tabiat dan keterbatasan manusia.
2. Solat Istikhoroh adalab solat yang dilakukan untuk minta petunjuk kepada Allah kebaikan perkara yang sedang dihadapi.
3. Para ulama bersepakat (ijma’) bahawa solat Istikhoroh hukumnya sunnah.
4. Solat Istikhoroh disunnahkan bagi segenap perkara baik besar atau kecil, selama seseorang bimbang atau ragu ataupun tidak mengetahui maslahatnya di masa akan datang/terkemudian.
5. Apabila sudah terdapat kecondongan hati atau mengetahui tentang baiknya perkara (dari awal lagi), maka tidak disunnahkan beristikhoroh, ini kerana solat Istikhoroh itu dilakukan adalah bagi tujuan meminta petunjuk, dan Allah memerintahkan hambanya yang telah melaksanakannya supya bertawakal kepada Allah.
6. Istikhoroh disunnahkan dalam perkara-perkara yang asalnya mubah, adapun perkara wajib dan sunnah, maka tidak disunnahkan istikhoroh, ini kerana kebaikannya sudah jelas adanya, sebagaimana perkara haram dan makruh tidak disunnahkan istikhoroh kerana keburukannya sudah jelas adanya.
7. Tidak terdapat dalil yang sah tentang pengkhususan bacaan surah-surah al-Qur’an dalam solat Istikhoroh.
8. Doa Istikhoroh boleh dibaca dalam solat (sebelum salam) atau di luar solat (sesudah salam)
9. Dibolehkan mengulangi solat Istikhoroh dalam satu perkara apabila diperlukan.
10. Ketenangan hati dan kelapangan dada kepada suatu perkara setelah melakukan solat istikhoroh adalah tanda petunjuk dari Allah, dan tidak terdapat dalil yang sah tentang keharusan melihat mimpi setelah beristikhoroh.
Demikianlah yang dapat dibentangkan dari beberapa penjelasan/keterangan para ulama tentang solat Istikhoroh, mudah-mudahan kita mendapat petunjuk dari Allah sehingga kita dapat melangkah sesuai dengan apa yang digariskan oleh Allah dan Rasul-Nya dan mendapatkan yang terbaik dan sisi-Nya dengan jalan taat dan istiqomah di atas landasan-Nya, amiin.
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