Công nghệ WIFI với cộng đồng

^ HOC UNG DUNG

CONG NGHE W1FI VffI C O N G DONG
Hoang Trung Dung

Wifi - Wireless Fidelity Id ten goi md cdc nhd sdn xuat ddt cho mdt
chuan ket ndi khdng ddy (IEEE 802.11), cdng nghe sit dung sdng radio
de thiet lap he thdng ket ndi mang khdng ddy. Vd cdng nghe Wifi trd
nen phd bien vd phdt trien manh a Viet Nam. Ddy Id cdng nghe mang
tien tien tren the gidi. Wifi ddc biet thich hap cho nhu cdu sit dung di
ddng vd cdc diem truy cap ddng ngudi ddng. Loai hinh dich vu ndy dd
gdp phdn thay ddi mot cdch ddng ke cudc sdng, thdi quen hdng ngdy
cua chung ta.
Wi-Fi va nhirng tien ich
Cdng nghe thdng tin dang phit triin nhu vu
bao, vi nd da tic ddng manh me tdi mgi mat
ddi sdng, xa hdi. Cudn theo dd li le Idi sinh
hoat, lim viec, hgc tip... Va wifi la mgt trong
nhiing cdng nghe diin hinh. Chung ta ching
cdn la gi vdi nhung quin cafe Internet ben
dudng, cac tip thi vi ci nhin su dung wifi.
Nhiiu ngudi xich laptop tdi nhirng quin cafe
wifi vdi muc dich thu giin, ludt web. gui
mail... vi cQng cd ngudi tdi day di thi hien
minh. Ngay tai nhung noi cdng cdng ta cung
cd Ihe bat gap nhieu ngudi hi hoiy ben chiic
miy tinh di ludt web, chat... Hien tai cic
trudng dai hgc trong nude diu cd phu sdng
wifi. de phuc vu mdt cich td't nhit nhu ciu
hgc tip vi giing giay ciia giing vien, cin bd,
sinh vien. Ddi vdi nhieu sinh vien, laptop li

mgt dung cu khdng the thiiu khi din trudng.
Binh thudng ngoii gid hgc phii sii dung miy
tinh. khi giii lag sinh vien ed the giii tri tren
Intemet qua sdng wifi eiia ndi bd tnrdng. Viec
ludt web qua wifi gin nhu da an siu vio thdi
quen cua nhiiu ngudi. chu yeu li thanh thieu
nien. sinh vien. Tuy nhien cd mdt bg phin ldn
ngudi truy cap wifi hien nay diu li dung
"liu", hg Igi dung su "thdng thoing" cua chi
wifi de dung thoii mii mi khdng phii tra tiin.
Ddi vdi nhung ngudi khdng cd diiu kien hoi
mang Intemet tai nhi. hoac khi di cdng tic.
thi viec truy cap mang diing "chua" wifi diin
ra mdt cich vd tu.
Khdng chi dimg lai d cic quin cafe, hien nay

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TAP CHf TIN HOC NGAN H A N G •

a cie thinh phd ldn nhu Hi Ndi, Tp. Hd Chi
Minh edn cd mdt "tri di Wi-Fi". Viec nhiiu
sinh vien lui tdi cic quin "tri di Wi-Fi", cd
thi giii thich bang ly do kinh te. Chi vdi
lOOOd tiin nude che hg cd thi tha hd hoi
mang, online... Mdt le duong nhien li chi cd
quin tri di nio "xjn" din muc di lip Wi-Fi di
miin phi khich hing chi tri 1.000 d cho mdt
lin ngdi quin ci. Thye ti, nhung quin tri di
ay vd tinh dugc "hudng xii" Wi-Fi tir nhung

dai nha hing, ci phe Wi-Fi. Ddi vdi nhieu
sinh vien, viec la ci cic khu cdng cdng di
dung chua wifi cd thi tiit kiem cho hg tiin
vao mang mdi ngiy. Ngudi tmy cip nhiiu cd
the tiit kiem hing tram ngin tien .net hing
thing. Thye ti thi ngdi ci phe Wi-Fi ehd yen
tinh vin thich, nhung vdi cic cd ciu sinh
vien, dieu dd khdng hgp li vi xa xi, nhit li
khi Wi-Fi di "phu sdng" via he! Dd cung li
li do khie'n nhiiu sinh vien khdng sir dung
djch vu Internet cd dinh.

Ld hdng cua mang khdng day wifi va
nhung he luy
Tuy cd nhiiu Igi ich, nhung Wifi cung gdp mdt
phin vio nhung nguyen nhin cho sy hgc hinh
sa Slit ciia ci biet mdt sd sinh vien liy cic cudc
vui diia, tieu khiin tren mang lim trgng. Khdng
it ban sinh vien khi gip thay vi hgc hinh, tim
tai lieu... mi cic ban lai sii dung wifi cd trong
trudng di choi game online, chat chit... Hg chg
ring viec trudng minh cd lip dat wifi li mgt co
hdi di "xii chua", thgii mii dgwnload. Thim
ehi cd nhiiu ban sir dung wifi di dny cap vio

$ 6 5(105) - 8/2009

nhung trang web "ban". Cic loai vin hda pham
ddi Qriy trong "the gidi ao" ludn ed sue hip dan
rat ldn ddi vdi hg. Tit nhien sd It niy rit di bj

sa nga, vudng vio cic te nan. Nhu vay ban da
khdng tin dung nhttng thuin Igi di giup minh
tie'n bd mi lai di nguge lai. Cd nhiiu ban, mac
du dang trong gid hgc, cung chat, choi game.
Viec lo li nhu viy se tao thinh mdt Id hdng
trong kiin thiic, va hg se ngiy cang xa rdi giing
dudng dai hgc. Diiu dd se anh hudng rat nhiiu
tdi tuong lai ciia cic ban.
Cdn trong nhiiu trudng hgp khic, nhiiu hd
gia dinh, doanh nghiep, tip thi kit ndi Internet khdng big ve dugc quyin tmy cap khdng
day cua hg bing mil khau va ma hda. Hg gin
nhu "di ngd cira" cho ngudi qua dudng va
hing xdm in cip quyin truy cap, vi di nhien
nhirng ke "an cip" niy khdng phii tri tiin cho
bat cu nhi cung cap dich vu Internet (ISP)
nio. Thudng thi viec su dung wifi "chia" Ii
hoin loan binh thudng, bdi nd it giy phuong
hai cho c. i thue bao wifi. Cd ching cung chi
la lim chim hon tdc do truy cap mang cia
chii sii dung. Tuy nhien diiu niy ehi xiy ra
khi ngudi ding nhiiu. De doa ldn nhat cua
viec xii chia wifi din tir cic tay hacker, ddi
vdi chung viec hack mang tmy cap Wi-Fi li
diiu khdng khd khin gi. Da cd nhiiu khuyin
cio cic chii hg gia dinh vi dganh nghiep dung
Intemet khdng diy nen thiet lip mang ludi vdi
nhung bien phap bio mat cao nhit, dim bao
sy ma hda manh me kjp thdi nhim ngin chan
tin tac (hacker) dung trdm, di phdng khi ning
bj liy cip ten ngudi dung (usemame), mit

TIN HOC UNG DUNG

khiu (password) vi cie thdng tin quan trgng
khic. Neu khdng ma hda mang ludi khdng
day, nhttng ke tdi pham io se theo ddi dugc
nhttng gi ban dang lam, du do chi li ludt Net
hay tmy cap tii lieu cdng viec tir xa. Thim
chi, chiing cd thi lim miy tinh cua ban bj lay
nhiim nhung ma ddc de tir dd lay cip thdng
tin nhin dang ci nhan. Bdi viy, kit ndi Wi-Fi
can dugc ma hda, ddng thdi chic chin mat
khau cua ban khdng di ding bj doin ra hoac
tan cdng. Cii khd li nhiiu thiit bj tiep nhin
sdng Wi-Fi hien nay cQa ngudi dung khdng
cd kha ning ty phdng ve trudc cic vu dot
nhap trii phip tir may
tinh cua ngudi khic, die
biet li tu nhinig hacker
chuyen nghiep. Trong
thuc ti da ghi nhin nhiiu
trudng hgp bj mat cip du
lieu bdi viec sii dung wifi.
Viec mat cip dtt lieu khi
dung wifi thudng xuat
phit tir su chu quan la Ii
cua ngudi ding, nim bit
dugc so hd niy, cic tay
hacker thudng tin cdng

vio cac laptop kit ndi wifi
cdng cdng. Bdi kit ndi vio
nhttng laptop niy vi an
trdm thdng tin hoin toin
khdng khd. Khi hacker
thiit lap miy laptop cua
anh ta cd cung ten vdi diim Qny cap (gidng nhu
cau hinh trong laptop), niu ngudi sir dung
khting biit mi kit ndi vio mang niy thi toin bd
thdng tin, dtt lieu, sd the tin dung cd thi di ding
bj hacker an trdm. Ldi khuyen trong mgi dndng
hgp la ngudi sii dung nen cd chi dd bag mat chg
miy cua minh ii bao toin du Ueu.

Will cho cdng ddng
Wifi cho phip ngudi sir dyng Qny cap mang
gidng nhu khi sir dung cdng nghe mang miy
linh tmyin thdng tai bit cir thdi diim nio
trong vung phu sdng. Them vio dd, Wifi cd
dd linh hoat vi khi ning phit friin mang ldn
do khdng bj inh hudng bdi viec thay ddi lai vj
tri, thiit ki lai mang miy tinh. Cung vi li
mang khdng diy nen Wifi khic phuc dugc
nhttng han chi vi dudng cip vat ly, giim dugc
nhieu chi phi hiin khai thi cdng day mang vi
khdng phii tic dOng nhiiu tdi co sd ha tang
ciia dd thj. Nim bat dugc nhttng uu diim dd.

hien nay tren the gidi da xuat hien nhieu du in
kit ndi cdng ddng bing viec phi sdng wifi

rdng khip trong thinh phd, vi thudng dugc
ggi vdi cii ten du in "thinh phd wifi". Trgng
du in niy, cic thiit bj phit sdng wifi se dugc
bd tri theo timg cum khu din cu, khu cdng
cdng... sdng wifi phit ra tir cic thiit bj niy se
giang kin toin bO thinh phd. Ngudi din trong
thinh phd se dugc su dung mien phi loai hinh
djch vu khdng day niy. Mgt van di dat ra li
khi nang bio mit dtt liiu ci nhin cHa ngudi
dung. Khi mdt cdng ddng cung sir dung wifi,
thi viec big mat cing dugc chu y day manh.

Bdi sd lugng ngudi diing ldn ddng thuin vdi
nd li hoat ddng gia ting cia hacker, vi se
dem den hau qui khdn ludng. Khi dd yeu ciu
dat ra vdi ngudi dung khdng chi dung lai d
muc dd su dung mil khau big ve. Bdi viec sir
dung mil khau bio ve miy tinh khi su dung
wifi hien nay chi gay them roue do khd cho
cic tay hacker mi thdi, miy tinh cua ban vin
chua the an toin myet ddi. Vi rdi van di niy
cung da cd giii phip khic phuc dua tren khia
canh ki thuat. Cie nhi cung cip djch vu da
dua ra nhieu y tudng, giai phip bio mil dugc
cho li rat an loan. Don cu nhu viec ung dung
chuong trinh khoi phan cung cua miy tinh.
Mgt khi eg sy xam nhap bat hgp phip, d cung
miy tinh se tu ddng ddng bing, cic du lieu ci
nhan trong miy tinh cua ban se dugc bio ve
tuyet ddi. Tit nhien li mudn dung dugc tien

ich niy thi ngudi su dung phii bd tiin tui.
Hien nay. nhung thinh cdng vi dich vy Inter-

net khdng day toin thinh phd diu din tu
nhiing noi thye su coi Wi-fi la mdt djch vu
cdng cdng. St. Cloud, mgt thinh phd cd
28.000 din d bang Horida. da cd mdt mang
Intemet khdng diy hoan loan miin phi. Mang
niy cQng cd nhirng van di cua no. Ching han
nhu nhimg diim "chit", nhung vin cd tdi hon
77% cdng din ciia thinh phd niy su dung.
Thanh phd Paris cung da tien hanh du in
thinh phd wifi, hg dang hy vgng se cd khoing
80% thinh phd dugc phii mang khdng day
vio cudi thip ky niy. Viec tray cap vao mang
Wi-Fi tai Paris se hoin toin miin phi vi dugc
duy tri bdi cic cdng ty
tu nhin. Cic diim tray
cap se dugc dit tai cic
khu vye cdng cdng vi
thu vien. Cdn tai nude
ta de in tren da dugc
nhi nude len phuong
in xay dyng, thi hien
qua cic cudc hgp cua
• •
chinh phu vi cic bd
trong nam 2008 vua
qua. Du in niy khi
thye hien thi irng dung

diu tien se la cic thinh
phd trung tim ci nude.
Hien tai hon 5000 diim
kit ndi Intemet khdng
day miin phi cua he
thd'ng Wifi FPT telecom da dugc thiit lip
tai thinh phd Hi Ndi vi tp. Hd Chi Minh.
Chuong trinh cd tdng sd vdn diu tu li 1,5
trieu USD, li giai doan dau tien trong tham
vgng bien 02 dd thj ldn niy thanh eac thinh
phd Wifi, phu sdng khip mgi noi di mgi
ngudi cd thi kit ndi Intemet mgi lie mgi noi
miin phi. Tuy nhien FPT se khdng miin phi
mai mai. Hg cung cap co sd ha ting cho Internet phit triin nhim qua dd ban cic dich vu
gia tri gia tang tren Internet nhu diin thoai Intemet, xem phim, nhac so. Vi mdi diy, bg
TT-TT da nhit tri cao vdi viec xiy dyng Sa Pa
thanh thinh phd Wi-Fi, coi dd la "thuang
hieu" du Ijch, cdng nghe cua Lio Cai. Mgt khi
cic cic dy in nay triin khai thinh cdng,
khdng nhung dat nude dugc ning len mdt tim
cao mdi vi khoa hgc cdng nghe, mi nd cdn
giup cdng ddng xich lai gin nhau hem. Va
chiing ta cung hy vgng vi mdt tuong lai tuoi
sing vdi djch vu wifi cho eOng ddng •

s6 5(105) - 8/2009 •

TAP CHf TN HOC NGAN HANG

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