What are the advantages and disadvantages of x2 and s1 for LTE system?
What do you mean advantage/disadvantage?
X2 will be done faster handover in LTE compare to s1 so x2 link are important to communicate between two eNB.
But if it belongs to different MME then X2 is not possible.
If x2 is faulty then s1 will work but link should be defined properly and not faulty.
Which means eNB defined handover will not take place & Normal handover will be the only option?
It routes through S1 in case of X2 not defined or sometimes X2 faulty situation too.
But X2 faulty situation can have prep fail in X2 HO.
T304 if less value and if you have major X2 issues or link missing then this value should be high.
Which you can have from X2 time handover.
Fast Handover execution is one advantage of X2 but there are other advantages of X2 for e.g information exchange for Load balancing through X2, Data forwarding through X2 in X2 handover, Inter cell interference coordination.