These are also called as Grid or Mesh network. Lattice networks are simply networks, where nodes are arranged in a rectangular lattice, aimed to overcome the major drawback of the ER model. Copy the link given below and paste it in new browser window to get more information on Lattice Network:- http://www.transtutors.com/homework-help/networks-systems/two-port-network/lattice-network/

2. Lattice
A lattice is an geometric arrangement of points that form a effective
structure for various points.

3. Lattice Network
 Lattice networks are simply networks where nodes are arranged
in a rectangular lattice, aimed to overcome the major drawback of
the ER model
 It is a symmetrical balanced network with four arms. The arms
consisting impedance ZA called series arms of the lattice network,
the next arms consisting of impedance ZB called shunt or
diagonal arms

4. Figure 2: (a) A Lattice Network (b) a lattice network rearranged as a bridge
(c) Zd = 0 in a lattice network

5. Circuit Analysis of Lattice Network
(a) Characteristic impedance (Z0)
Z0 = √ZA · ZB
(b) In terms of open and short circuit impedances
Z0 = √ZOC · ZSC
(c) Propagation constant (γ)
γ = ln [Z0 + ZA] = ln [ZB + ZO]
[Z0 – ZA] [ZB – Z0]
(d) Impedance ZA and ZB interms of characteristic impedance (Z0)
and propagation constant (γ)
ZB = Z0 · coth γ/2

6. Fig 3: open and short circuit impedances of symmetrical lattice network
Fig 5: Symmetrical Lattice Network Impedances Interms of Z0 and γ

7. Z parameters of Lattice Network
V2 = (Za + Zc) (Zd + Zb)
I2 Za + Zd + Zc + Zd
If the network is symmetric, Za = Z
Fig 6: lattice network is redrawn using Z parameters